SeekBarVolumizer: Use TAG for sample sound

LeAudio configures its streams based on the audio metadata.
When user sets different volume with SeekBarVolumizer, LeAudio gets
metadata which are assign to valid scenarios like phone call/media and
tries to create stream for that scenario.
Issue happens when e.g. during media stream, user is changing volume
for ringtone or  conversational as it will result with stream
reconfiguration on the LeAudio side. This will stop stream for a moment
and creates lower quality stream for converstational.

With this patch,by adding "VX_AOSP_SAMPLESOUND" tag, LeAudio code has a chance
to behave correctly on sample sound.

Bug: 274106369
Test: Manual test
Tag: #feature

Change-Id: I5f7186c076a99cf712d82903fe584a6303d49ffa