Add support to get registered policy mixes

This new (Test)Api exposes all AudioMixes registered with AudioPolicyManager.
The TestApi is very useful in verifying AudioMix/AudioPolicy behavior in
the Java and Native layer to debug and assert the correct behavior.

Bug: 309080867
Test: atest AudioHostTest

Change-Id: Icdc2a482228ab06ac7386915ddbeb0cfcc24889d
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index 6e1ecec..2a4c069 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -1810,6 +1810,23 @@
     }
 }
 
+Status
+AudioPolicyService::getRegisteredPolicyMixes(std::vector<::android::media::AudioMix>* mixesAidl) {
+    if (mAudioPolicyManager == nullptr) {
+        return binderStatusFromStatusT(NO_INIT);
+    }
+
+    std::vector<AudioMix> mixes;
+    int status = mAudioPolicyManager->getRegisteredPolicyMixes(mixes);
+
+    for (const auto& mix : mixes) {
+        media::AudioMix aidlMix = VALUE_OR_RETURN_BINDER_STATUS(legacy2aidl_AudioMix(mix));
+        mixesAidl->push_back(aidlMix);
+    }
+
+    return binderStatusFromStatusT(status);
+}
+
 Status AudioPolicyService::updatePolicyMixes(
         const ::std::vector<::android::media::AudioMixUpdate>& updates) {
     audio_utils::lock_guard _l(mMutex);
diff --git a/services/audiopolicy/service/AudioPolicyService.cpp b/services/audiopolicy/service/AudioPolicyService.cpp
index aed6458..bc6498a 100644
--- a/services/audiopolicy/service/AudioPolicyService.cpp
+++ b/services/audiopolicy/service/AudioPolicyService.cpp
@@ -166,7 +166,8 @@
 BINDER_METHOD_ENTRY(setPreferredMixerAttributes) \
 BINDER_METHOD_ENTRY(getPreferredMixerAttributes) \
 BINDER_METHOD_ENTRY(clearPreferredMixerAttributes) \
-
+BINDER_METHOD_ENTRY(getRegisteredPolicyMixes) \
+                                                     \
 // singleton for Binder Method Statistics for IAudioPolicyService
 static auto& getIAudioPolicyServiceStatistics() {
     using Code = int;
@@ -1348,7 +1349,8 @@
         case TRANSACTION_getDevicesForRoleAndCapturePreset:
         case TRANSACTION_getSpatializer:
         case TRANSACTION_setPreferredMixerAttributes:
-        case TRANSACTION_clearPreferredMixerAttributes: {
+        case TRANSACTION_clearPreferredMixerAttributes:
+        case TRANSACTION_getRegisteredPolicyMixes: {
             if (!isServiceUid(IPCThreadState::self()->getCallingUid())) {
                 ALOGW("%s: transaction %d received from PID %d unauthorized UID %d",
                       __func__, code, IPCThreadState::self()->getCallingPid(),
diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index 9a8a056..101b90c 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -311,6 +311,8 @@
     binder::Status clearPreferredMixerAttributes(const media::audio::common::AudioAttributes& attr,
                                                  int32_t portId,
                                                  int32_t uid) override;
+    binder::Status getRegisteredPolicyMixes(
+            std::vector <::android::media::AudioMix>* mixes) override;
 
     status_t onTransact(uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags) override;