27607 Revert “Use a Pbuffer surface when the onscreen surface is not available for snapshotting on Android” (platform-android, cla: yes)

27629 Reland use a pbuffer surface when in the background (platform-android, cla: yes)

27645 Use preDraw for the Android embedding (platform-android, cla: yes, waiting for tree to go green)

27646 Set AppStartUp UserTag from engine (platform-android, cla: yes, waiting for tree to go green)

27655 Fix NPE and remove global focus listener when tearing down the view (platform-android, cla: yes, waiting for tree to go green, needs tests)

27671 Fix NPE and remove global focus listener when tearing down the view (… (platform-android, cla: yes)