Only the primary HAL has to support mic mute function.
Ignore errors returned by other HALs in setMicMute() and
only report mic mute state from primary HAL in getMicMute().
Bug: 153103117
Test: CTS AudioManagerTest.testMicrophoneMute
Test: manual phone call and verify microphone mute.
Change-Id: Ic121c49e7e7cd75eeee9342249271c7fca7c1c2a