Allow for late audio module discovery in APM

Extract code that loads hardware modules and fills out
mAvailable{Input|Output}Devices into a reusable function.
It is used both during APM initialization and on
receiving a notification that a new HAL service has
been discovered.

Bug: 149854039
Test: atest audiopolicy_tests
Change-Id: Ifb7f0b61b06a0609802e63dccb26f3472328ef48
diff --git a/services/audiopolicy/managerdefault/AudioPolicyManager.h b/services/audiopolicy/managerdefault/AudioPolicyManager.h
index b0adbc7..8121f86 100644
--- a/services/audiopolicy/managerdefault/AudioPolicyManager.h
+++ b/services/audiopolicy/managerdefault/AudioPolicyManager.h
@@ -325,6 +325,8 @@
 
         bool isCallScreenModeSupported() override;
 
+        void onNewAudioModulesAvailable() override;
+
         status_t initialize();
 
 protected:
@@ -729,6 +731,8 @@
         SwAudioOutputCollection mPreviousOutputs;
         AudioInputCollection mInputs;     // list of input descriptors
 
+        DeviceVector  mOutputDevicesAll; // all output devices from the config
+        DeviceVector  mInputDevicesAll;  // all input devices from the config
         DeviceVector  mAvailableOutputDevices; // all available output devices
         DeviceVector  mAvailableInputDevices;  // all available input devices
 
@@ -739,9 +743,8 @@
 
         EffectDescriptorCollection mEffects;  // list of registered audio effects
         sp<DeviceDescriptor> mDefaultOutputDevice; // output device selected by default at boot time
-        HwModuleCollection mHwModules; // contains only modules that have been loaded successfully
-        HwModuleCollection mHwModulesAll; // normally not needed, used during construction and for
-                                          // dumps
+        HwModuleCollection mHwModules; // contains modules that have been loaded successfully
+        HwModuleCollection mHwModulesAll; // contains all modules declared in the config
 
         AudioPolicyConfig mConfig;