Fix clang-tidy warnings in audio and playerservice.

* Add explicit keyword to conversion constructors.
Bug: 28341362
* Use const reference type for read-only parameters.
Bug: 30407689
Test: build with WITH_TIDY=1

Change-Id: I265f3b094e08d5705b506b3fbba51439c134af84
diff --git a/services/audiopolicy/service/AudioPolicyEffects.h b/services/audiopolicy/service/AudioPolicyEffects.h
index f68966f..9428409 100644
--- a/services/audiopolicy/service/AudioPolicyEffects.h
+++ b/services/audiopolicy/service/AudioPolicyEffects.h
@@ -136,7 +136,7 @@
     // class to store voctor of AudioEffects
     class EffectVector {
     public:
-        EffectVector(audio_session_t session) : mSessionId(session), mRefCount(0) {}
+        explicit EffectVector(audio_session_t session) : mSessionId(session), mRefCount(0) {}
         /*virtual*/ ~EffectVector() {}
 
         // Enable or disable all effects in effect vector
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index dc45a54..f6da920 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -694,7 +694,7 @@
     return mAudioPolicyManager->releaseSoundTriggerSession(session);
 }
 
-status_t AudioPolicyService::registerPolicyMixes(Vector<AudioMix> mixes, bool registration)
+status_t AudioPolicyService::registerPolicyMixes(const Vector<AudioMix>& mixes, bool registration)
 {
     Mutex::Autolock _l(mLock);
     if(!modifyAudioRoutingAllowed()) {
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImplLegacy.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImplLegacy.cpp
index 612076b..517fba1 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImplLegacy.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImplLegacy.cpp
@@ -602,7 +602,7 @@
     return INVALID_OPERATION;
 }
 
-status_t AudioPolicyService::registerPolicyMixes(Vector<AudioMix> mixes __unused,
+status_t AudioPolicyService::registerPolicyMixes(const Vector<AudioMix>& mixes __unused,
                                                  bool registration __unused)
 {
     return INVALID_OPERATION;
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp
index d24e9a0..52ed73e 100644
--- a/services/audiopolicy/service/AudioPolicyService.cpp
+++ b/services/audiopolicy/service/AudioPolicyService.cpp
@@ -221,14 +221,14 @@
     }
 }
 
-void AudioPolicyService::onDynamicPolicyMixStateUpdate(String8 regId, int32_t state)
+void AudioPolicyService::onDynamicPolicyMixStateUpdate(const String8& regId, int32_t state)
 {
     ALOGV("AudioPolicyService::onDynamicPolicyMixStateUpdate(%s, %d)",
             regId.string(), state);
     mOutputCommandThread->dynamicPolicyMixStateUpdateCommand(regId, state);
 }
 
-void AudioPolicyService::doOnDynamicPolicyMixStateUpdate(String8 regId, int32_t state)
+void AudioPolicyService::doOnDynamicPolicyMixStateUpdate(const String8& regId, int32_t state)
 {
     Mutex::Autolock _l(mNotificationClientsLock);
     for (size_t i = 0; i < mNotificationClients.size(); i++) {
@@ -310,7 +310,7 @@
 }
 
 void AudioPolicyService::NotificationClient::onDynamicPolicyMixStateUpdate(
-        String8 regId, int32_t state)
+        const String8& regId, int32_t state)
 {
     if (mAudioPolicyServiceClient != 0) {
         mAudioPolicyServiceClient->onDynamicPolicyMixStateUpdate(regId, state);
@@ -857,7 +857,7 @@
 }
 
 void AudioPolicyService::AudioCommandThread::dynamicPolicyMixStateUpdateCommand(
-        String8 regId, int32_t state)
+        const String8& regId, int32_t state)
 {
     sp<AudioCommand> command = new AudioCommand();
     command->mCommand = DYN_POLICY_MIX_STATE_UPDATE;
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 0b2cb35..def6405 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -196,7 +196,7 @@
 
     virtual audio_mode_t getPhoneState();
 
-    virtual status_t registerPolicyMixes(Vector<AudioMix> mixes, bool registration);
+    virtual status_t registerPolicyMixes(const Vector<AudioMix>& mixes, bool registration);
 
     virtual status_t startAudioSource(const struct audio_port_config *source,
                                       const audio_attributes_t *attributes,
@@ -227,8 +227,8 @@
             void onAudioPatchListUpdate();
             void doOnAudioPatchListUpdate();
 
-            void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state);
-            void doOnDynamicPolicyMixStateUpdate(String8 regId, int32_t state);
+            void onDynamicPolicyMixStateUpdate(const String8& regId, int32_t state);
+            void doOnDynamicPolicyMixStateUpdate(const String8& regId, int32_t state);
             void onRecordingConfigurationUpdate(int event, audio_session_t session,
                     audio_source_t source, const audio_config_base_t *clientConfig,
                     const audio_config_base_t *deviceConfig, audio_patch_handle_t patchHandle);
@@ -305,7 +305,7 @@
                     void        updateAudioPatchListCommand();
                     status_t    setAudioPortConfigCommand(const struct audio_port_config *config,
                                                           int delayMs);
-                    void        dynamicPolicyMixStateUpdateCommand(String8 regId, int32_t state);
+                    void        dynamicPolicyMixStateUpdateCommand(const String8& regId, int32_t state);
                     void        recordingConfigurationUpdateCommand(
                                                         int event, audio_session_t session,
                                                         audio_source_t source,
@@ -424,7 +424,7 @@
     class AudioPolicyClient : public AudioPolicyClientInterface
     {
      public:
-        AudioPolicyClient(AudioPolicyService *service) : mAudioPolicyService(service) {}
+        explicit AudioPolicyClient(AudioPolicyService *service) : mAudioPolicyService(service) {}
         virtual ~AudioPolicyClient() {}
 
         //
@@ -539,7 +539,7 @@
 
                             void      onAudioPortListUpdate();
                             void      onAudioPatchListUpdate();
-                            void      onDynamicPolicyMixStateUpdate(String8 regId, int32_t state);
+                            void      onDynamicPolicyMixStateUpdate(const String8& regId, int32_t state);
                             void      onRecordingConfigurationUpdate(
                                         int event, audio_session_t session,
                                         audio_source_t source,