Adding conversion support for AUDIO_PORT_CONFIG_GAIN

Bug: 172829688
Test: Ran against target that was getting unexpected before and after to
verify no longer the case

Change-Id: Ic3301bd103088fabb2eb8ced0dc667bcbdacf15d
diff --git a/media/libaudioclient/AidlConversion.cpp b/media/libaudioclient/AidlConversion.cpp
index d362d8f..681d4d7 100644
--- a/media/libaudioclient/AidlConversion.cpp
+++ b/media/libaudioclient/AidlConversion.cpp
@@ -299,11 +299,12 @@
             return AUDIO_PORT_CONFIG_CHANNEL_MASK;
         case media::AudioPortConfigType::FORMAT:
             return AUDIO_PORT_CONFIG_FORMAT;
+        case media::AudioPortConfigType::GAIN:
+            return AUDIO_PORT_CONFIG_GAIN;
         case media::AudioPortConfigType::FLAGS:
             return AUDIO_PORT_CONFIG_FLAGS;
-        default:
-            return unexpected(BAD_VALUE);
     }
+    return unexpected(BAD_VALUE);
 }
 
 // The legacy enum is unnamed. Thus, we use int.
@@ -315,11 +316,12 @@
             return media::AudioPortConfigType::CHANNEL_MASK;
         case AUDIO_PORT_CONFIG_FORMAT:
             return media::AudioPortConfigType::FORMAT;
+        case AUDIO_PORT_CONFIG_GAIN:
+            return media::AudioPortConfigType::GAIN;
         case AUDIO_PORT_CONFIG_FLAGS:
             return media::AudioPortConfigType::FLAGS;
-        default:
-            return unexpected(BAD_VALUE);
     }
+    return unexpected(BAD_VALUE);
 }
 
 ConversionResult<unsigned int> aidl2legacy_int32_t_config_mask(int32_t aidl) {