Save or destroy activity surface based on property

With changed Android-N behaviour, not all surfaces will be
destroyed for BG apps. Based on persist.sys.disableSaveSurface
property we can destroy or save activity's surface once
its animation locked or activityStoped.

Change-Id: Ia68de9e0b7b85b4791bef61efb618c1c36c5ccc1
1 file changed