DO NOT MERGE Remove window obscurement information.

If ACTION_OUTSIDE_EVENTS contain information about whether the touch is
obscured, then a pattern of invisible, untouchable, unfocusable
SYSTEM_ALERT_WINDOWS can be placed across the screen to determine
approximate locations of touch events without the user knowing.

Bug: 31097064
Test: cts-tradefed run cts --class android.security.cts.MotionEventTest
Change-Id: Iebbb68231cbb76f87241201e7640a1fe3e188625
(cherry picked from commit 5508ca2c)