add support more PCM encoding and avoid overwriting audio format

 - add 32 bit PCM and 24 bit packed PCM format conversion.
 - avoid overwriting audio format in the PCM offloading case

Bug: 357483620
Test: PCM offload playback
Flag: EXEMPT bugfix
Change-Id: Ia93aebb192b5ed6b3e315dbc962cfb11a1cb66b5