Merge "Spatializer: document state getters when feature is unsupported" into...

Merge "Spatializer: document state getters when feature is unsupported" into sc-v2-dev am: 2f645f23

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/16040116

Change-Id: Ib696a1ee204814123e09c81949056b633ccd1889