add flag for CS aduio flicker

b/290847206 was merged to V without a flag to gate the new logic.
This CL gates all the changes in b/290847206 and updates 2 tests.

Fixes: 309540769
Bug: 290847206 (original bug)
Test: updated 2 unit tests
Change-Id: I05dfa70e06154f3f8a114455432e04b0e77b3a56