Switch the order of calls in setStreamVolume

The setStreamVolume implementation has a different order of execution
than adjustStreamVolume. The postSetLeVolume is called first followed by
setting the index on the VSS and lastly the mute state is adjusted. This
could lead to a race condition when the LeService is checking the mute
state of the stream that is changing volume.

Adjusted the order of calls in setStreamVolume to match the one in
adjusStreamVolume. The calls into the BT stack are called after the
index and mute state is adjusted.

Test: adb shell device_config put media_audio
com.android.media.audio.volume_refactoring true
Test: manual & atest AudioManagerTests
Bug: 329202581

Change-Id: I66e2a9f390725a0cafca779436e507f5321a0ece