AudioService: SpatializerHelper queries spatialized masks

SpatializerHelper queries and logs the Spatializer effect's
spatialized channel masks.
Add convenience method in AudioFormat to output a human-readable
string from a java channel mask.

Bug: 377582613
Flag: android.media.audio.spatializer_capabilities
Test: adb shell dumpsys audio | grep "Spatial audio" -A 7
Change-Id: Iae41d31d8d8a5729a3b5c8fa0d0a2b9077466129