AudioService: setDeviceVolume shouln't change the mute state

Do not allow the codepath for setDeviceVolume to alter the
mute state of a stream.

Bug: 266211560
Test: adb shell dumpsys audio in silent mode after reboot
Change-Id: I4da94d75a1396fc6d1486a0955fb537b7638e9d6
Merged-In: I4da94d75a1396fc6d1486a0955fb537b7638e9d6