Add inherit mode to audio port gain config

The mode is required to correctly change the volume at the audio control
HAL v7 and above, as newer versions have an optional gain which will be
skipped if the mode is not correctly set.

Bug: 340540043
Test: m -j, manual audio test
Change-Id: I2a435807921eebd3c4a3e409b460ea854b590172
diff --git a/services/audiopolicy/common/managerdefinitions/src/AudioOutputDescriptor.cpp b/services/audiopolicy/common/managerdefinitions/src/AudioOutputDescriptor.cpp
index d027564..747af4a 100644
--- a/services/audiopolicy/common/managerdefinitions/src/AudioOutputDescriptor.cpp
+++ b/services/audiopolicy/common/managerdefinitions/src/AudioOutputDescriptor.cpp
@@ -561,6 +561,7 @@
             audio_port_config config = {};
             devicePort->toAudioPortConfig(&config);
             config.config_mask = AUDIO_PORT_CONFIG_GAIN;
+            config.gain.mode = gains[0]->getMode();
             config.gain.values[0] = gainValueMb;
             return mClientInterface->setAudioPortConfig(&config, 0) == NO_ERROR;
         }