b89ce43499
This lets us avoid a Binder roundtrip to the system process during volume changes. Previously volume change would be staged at key-down, then applied at key up in tandem with playback of the sonic feedback about volume key presses. The reason for this two-stage handling was to defer playback of the sound [at the target volume] while the volume key was being held for repeat. On some devices volume is always sent as key down/up pairs rather than down-repeat-up sequences. On these devices it is more efficient to apply the new volume immediately during down handling, and have the up handling be a no-op. This CL adds a configuration resource item selecting this new fast path. Bug 6433943 Change-Id: Icffa56e958243b841d514e2fe4609ba3a7b20f14