Plumb the notification about audio HAL services update to APM

AudioFlinger registers a callback with libaudiohal to receive
notifications when new HAL services get registered. It relays
the notification to AudioPolicyManager via AudioSystem /
IAudioPolicyService interface.

Because AF / APM only interact via Binder interfaces and APM's
interface gets registered later than AF's, the notification
from AF is made asynchronous.

Bug: 149854039
Test: audio test on a regular phone configuration
      audio test on a phone with MSD audio HAL module
Change-Id: I158e941b8f75e2a4614b9d84ca798b0f1f47aa6a
Merged-In: I158e941b8f75e2a4614b9d84ca798b0f1f47aa6a
diff --git a/media/libaudioclient/AudioSystem.cpp b/media/libaudioclient/AudioSystem.cpp
index 480930b..481becc 100644
--- a/media/libaudioclient/AudioSystem.cpp
+++ b/media/libaudioclient/AudioSystem.cpp
@@ -783,6 +783,13 @@
 
 // ---------------------------------------------------------------------------
 
+void AudioSystem::onNewAudioModulesAvailable()
+{
+    const sp<IAudioPolicyService>& aps = AudioSystem::get_audio_policy_service();
+    if (aps == 0) return;
+    aps->onNewAudioModulesAvailable();
+}
+
 status_t AudioSystem::setDeviceConnectionState(audio_devices_t device,
                                                audio_policy_dev_state_t state,
                                                const char *device_address,
diff --git a/media/libaudioclient/IAudioPolicyService.cpp b/media/libaudioclient/IAudioPolicyService.cpp
index 0facaf8..24d7c92 100644
--- a/media/libaudioclient/IAudioPolicyService.cpp
+++ b/media/libaudioclient/IAudioPolicyService.cpp
@@ -108,6 +108,7 @@
     SET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY,
     REMOVE_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY,
     GET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY,
+    AUDIO_MODULES_UPDATED,  // oneway
 };
 
 #define MAX_ITEMS_PER_LIST 1024
@@ -1336,6 +1337,13 @@
         }
         return static_cast<status_t>(reply.readInt32());
     }
+
+    virtual void onNewAudioModulesAvailable()
+    {
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioPolicyService::getInterfaceDescriptor());
+        remote()->transact(AUDIO_MODULES_UPDATED, data, &reply, IBinder::FLAG_ONEWAY);
+    }
 };
 
 IMPLEMENT_META_INTERFACE(AudioPolicyService, "android.media.IAudioPolicyService");
@@ -1401,7 +1409,8 @@
         case SET_RTT_ENABLED:
         case SET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY:
         case REMOVE_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY:
-        case GET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY: {
+        case GET_PREFERRED_DEVICE_FOR_PRODUCT_STRATEGY:
+        case AUDIO_MODULES_UPDATED: {
             if (!isServiceUid(IPCThreadState::self()->getCallingUid())) {
                 ALOGW("%s: transaction %d received from PID %d unauthorized UID %d",
                       __func__, code, IPCThreadState::self()->getCallingPid(),
@@ -2458,6 +2467,12 @@
             return NO_ERROR;
         }
 
+        case AUDIO_MODULES_UPDATED: {
+            CHECK_INTERFACE(IAudioPolicyService, data, reply);
+            onNewAudioModulesAvailable();
+            return NO_ERROR;
+        } break;
+
         default:
             return BBinder::onTransact(code, data, reply, flags);
     }
diff --git a/media/libaudioclient/include/media/AudioSystem.h b/media/libaudioclient/include/media/AudioSystem.h
index a86297d..925bc89 100644
--- a/media/libaudioclient/include/media/AudioSystem.h
+++ b/media/libaudioclient/include/media/AudioSystem.h
@@ -211,6 +211,7 @@
     //
     // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
     //
+    static void onNewAudioModulesAvailable();
     static status_t setDeviceConnectionState(audio_devices_t device, audio_policy_dev_state_t state,
                                              const char *device_address, const char *device_name,
                                              audio_format_t encodedFormat);
diff --git a/media/libaudioclient/include/media/IAudioPolicyService.h b/media/libaudioclient/include/media/IAudioPolicyService.h
index 9b91d6d..3edac33 100644
--- a/media/libaudioclient/include/media/IAudioPolicyService.h
+++ b/media/libaudioclient/include/media/IAudioPolicyService.h
@@ -42,6 +42,7 @@
     //
     // IAudioPolicyService interface (see AudioPolicyInterface for method descriptions)
     //
+    virtual void onNewAudioModulesAvailable() = 0;
     virtual status_t setDeviceConnectionState(audio_devices_t device,
                                               audio_policy_dev_state_t state,
                                               const char *device_address,