Change InputWindowInfo::isTrustedOverlay() to be permission and flag based

Add private flag to WindowManager.LayoutParams. If the flag is set,
check if caller has INTERNAL_SYSTEM_WINDOW permission.

Bug: 155781676
Bug: 196389741
Test: atest WindowManagerServiceTests
Change-Id: I70151697cc01e8427129f951f0ebadc4805b2d56
Merged-In: I70151697cc01e8427129f951f0ebadc4805b2d56
11 files changed