Don't consume volume up/down key events in PlatformAndroid
Merge pull request #1418 from rgngl/androidVolumeKeyFix

Don't consume volume up/down key events in PlatformAndroid
UI layout optimizations.
Updated UI controls to track dirty state in such a way that layouts should no longer occur every frame. Layout should now only happen when a control is resized or some other property affecting layout changes.
For optimization purposes, UI now determines layout and auto-sizing based on the NORMAL UI/input state. This means that you cannot have a hover or active state for a UI control that changes the size of the control.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next