audio HAL: add output flag indicating support for gapless transitions

Add output profile flag AUDIO_OUTPUT_FLAG_GAPLESS_OFFLOAD to be used in
conjunction with AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD to indicate
that gapless transitions are supported when playing compressed audio.

Bug: 158191844
Test: make
Change-Id: Ifa551ff36d8571062cac3ad38f89be2f3addb960
diff --git a/audio/7.0/config/audio_policy_configuration.xsd b/audio/7.0/config/audio_policy_configuration.xsd
index 56b3a27..a735c6d 100644
--- a/audio/7.0/config/audio_policy_configuration.xsd
+++ b/audio/7.0/config/audio_policy_configuration.xsd
@@ -181,6 +181,7 @@
             <xs:enumeration value="AUDIO_OUTPUT_FLAG_MMAP_NOIRQ" />
             <xs:enumeration value="AUDIO_OUTPUT_FLAG_VOIP_RX" />
             <xs:enumeration value="AUDIO_OUTPUT_FLAG_INCALL_MUSIC" />
+            <xs:enumeration value="AUDIO_OUTPUT_FLAG_GAPLESS_OFFLOAD" />
             <xs:enumeration value="AUDIO_INPUT_FLAG_NONE" />
             <xs:enumeration value="AUDIO_INPUT_FLAG_FAST" />
             <xs:enumeration value="AUDIO_INPUT_FLAG_HW_HOTWORD" />