audio: add reporting of gapless playback support

Add reporting of gapless playback support via
getOffloadSupport() method which replaces isOffloadSupported().
The audio HAL implementation indicates gapless support by setting flag
AUDIO_OUTPUT_FLAG_GAPLESS_OFFLOAD on an output profile in addition to
flag AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD.

Bug: 158191844
Test: make
Change-Id: I7a8fa284c2486fd7a74782acb1ac7537d1534e49
diff --git a/media/libaudioclient/AidlConversion.cpp b/media/libaudioclient/AidlConversion.cpp
index 681d4d7..314b33d 100644
--- a/media/libaudioclient/AidlConversion.cpp
+++ b/media/libaudioclient/AidlConversion.cpp
@@ -659,6 +659,8 @@
             return AUDIO_OUTPUT_FLAG_VOIP_RX;
         case media::AudioOutputFlags::INCALL_MUSIC:
             return AUDIO_OUTPUT_FLAG_INCALL_MUSIC;
+        case media::AudioOutputFlags::GAPLESS_OFFLOAD:
+            return AUDIO_OUTPUT_FLAG_GAPLESS_OFFLOAD;
         default:
             return unexpected(BAD_VALUE);
     }
@@ -697,6 +699,8 @@
             return media::AudioOutputFlags::VOIP_RX;
         case AUDIO_OUTPUT_FLAG_INCALL_MUSIC:
             return media::AudioOutputFlags::INCALL_MUSIC;
+        case AUDIO_OUTPUT_FLAG_GAPLESS_OFFLOAD:
+            return media::AudioOutputFlags::GAPLESS_OFFLOAD;
         default:
             return unexpected(BAD_VALUE);
     }