Add AudioGain* to android.media.audio.common

a.m.a.c adds AudioGain* types which are similar to
the ones from Audio HIDL HAL V7.

Bug: 198812639
Test: m
Change-Id: I6471d3a85fea81e45357f5d7e4363313bd36f7c7
diff --git a/media/Android.bp b/media/Android.bp
index ad4f96c..22bbdb6 100644
--- a/media/Android.bp
+++ b/media/Android.bp
@@ -65,6 +65,9 @@
         "aidl/android/media/audio/common/AudioEncapsulationType.aidl",
         "aidl/android/media/audio/common/AudioFormatDescription.aidl",
         "aidl/android/media/audio/common/AudioFormatType.aidl",
+        "aidl/android/media/audio/common/AudioGain.aidl",
+        "aidl/android/media/audio/common/AudioGainConfig.aidl",
+        "aidl/android/media/audio/common/AudioGainMode.aidl",
         "aidl/android/media/audio/common/AudioMMapPolicy.aidl",
         "aidl/android/media/audio/common/AudioMMapPolicyInfo.aidl",
         "aidl/android/media/audio/common/AudioMMapPolicyType.aidl",