Fix PrimaryDevice::setMasterVolume/getMasterVolume

VtsHalAudioV6_0TargetTest expects the same value back
in getMasterVolume as it was set with setMasterVolume,
also check for NaN.

Bug: 157158109
Test: atest VtsHalAudioV6_0TargetTest
Change-Id: I378c2a183d7ee2e4fa2896aeee8c5cbda1a3c094
Merged-In: I378c2a183d7ee2e4fa2896aeee8c5cbda1a3c094
2 files changed