Audio Aidl: Unify naming for conversion methods

Most of the naming for aidl2legacy and legacy2aidl
are consistent, correct the few remaining inconsistencies.

Test: compiles, boots
Bug: 175316373
Change-Id: I85952846b306a2b5e88db125ccfbe431cc9bd7cd
diff --git a/media/libaudiofoundation/AudioGain.cpp b/media/libaudiofoundation/AudioGain.cpp
index 56343d8..1dee938 100644
--- a/media/libaudiofoundation/AudioGain.cpp
+++ b/media/libaudiofoundation/AudioGain.cpp
@@ -140,7 +140,7 @@
     parcelable->useInChannelMask = mUseInChannelMask;
     parcelable->useForVolume = mUseForVolume;
     parcelable->mode = VALUE_OR_RETURN_STATUS(
-            legacy2aidl_audio_gain_mode_t_mask_int32_t(mGain.mode));
+            legacy2aidl_audio_gain_mode_t_int32_t_mask(mGain.mode));
     parcelable->channelMask = VALUE_OR_RETURN_STATUS(
             legacy2aidl_audio_channel_mask_t_int32_t(mGain.channel_mask));
     parcelable->minValue = VALUE_OR_RETURN_STATUS(convertIntegral<int32_t>(mGain.min_value));