audio: hal: add channel count check for channel mask update

[Issue]: audio record CTS test case AudioNativeTest#testRecordStreamData is failing
[Rootcause]: the existing change is made as part of 10ch FR
and causing CTS test case failure as it is updating
channel mask while audio capture.
[Fix]: added channel count 6 to avoid channel mask update and restore to original
conditional check

Change-Id: I7e2818dc89f91fa3c64f667befe1c76eabd2eb00