Revert "Rename AudioGain.useInChannelMask -> isInput" This reverts commit e028aed5290a98f5e8523ce37595e28aaa838c63. Reason for revert: Android Auto regression b/194987848 Change-Id: I80ce258defca1a1c75e8a4c656690bd8cf809331 (cherry picked from commit 05399f489aece403775f34cd2c2233243e2d5654)