Revert "audio: allow standby for direct track"

This reverts commit 9cd7ad101315e0bff4c5f171706c6f80c7e22644.

Prior CL allows Direct PCM tracks to enter standby on pause
which unfortunately causes timestamp frame position to reset to 0.

Test: Audio sanity test
Test: Verified in bug to remove the regression above.
Bug: 157609403
Change-Id: I5e0d43a0e50981a300bc05711b71efe0b7e22f98
1 file changed