Add AudioChannelMask to Framework SAIDL definition

Framework SAIDL used to use 'int' for the channel mask
type. To help finding all the places where channel masks
are used, add a designated type. Currently it's an enum,
but it will be changed to a more extendable type soon (see
the bug and the plan document).

Bug: 188932434
Test: m
Change-Id: If2d958fcc92b8e549493d3fa83b35c12dcda2ccc
diff --git a/media/libaudiofoundation/AudioGain.cpp b/media/libaudiofoundation/AudioGain.cpp
index 1dee938..5cc2b2f 100644
--- a/media/libaudiofoundation/AudioGain.cpp
+++ b/media/libaudiofoundation/AudioGain.cpp
@@ -142,7 +142,7 @@
     parcelable->mode = VALUE_OR_RETURN_STATUS(
             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));
+            legacy2aidl_audio_channel_mask_t_AudioChannelMask(mGain.channel_mask));
     parcelable->minValue = VALUE_OR_RETURN_STATUS(convertIntegral<int32_t>(mGain.min_value));
     parcelable->maxValue = VALUE_OR_RETURN_STATUS(convertIntegral<int32_t>(mGain.max_value));
     parcelable->defaultValue = VALUE_OR_RETURN_STATUS(
@@ -166,7 +166,7 @@
     mGain.mode = VALUE_OR_RETURN_STATUS(
             aidl2legacy_int32_t_audio_gain_mode_t_mask(parcelable.mode));
     mGain.channel_mask = VALUE_OR_RETURN_STATUS(
-            aidl2legacy_int32_t_audio_channel_mask_t(parcelable.channelMask));
+            aidl2legacy_AudioChannelMask_audio_channel_mask_t(parcelable.channelMask));
     mGain.min_value = VALUE_OR_RETURN_STATUS(convertIntegral<int>(parcelable.minValue));
     mGain.max_value = VALUE_OR_RETURN_STATUS(convertIntegral<int>(parcelable.maxValue));
     mGain.default_value = VALUE_OR_RETURN_STATUS(convertIntegral<int>(parcelable.defaultValue));