Lockscreen: Restrict double taps to prevent falsing

Further restricts the second tap on ActivateableNotificationView
such that it must occur no further than 0.2in from the first tap.

Bug: 32766052
Change-Id: I033c1abc64c815d519153ced23ac9751471b1d05
Test: Tap notification on lockscreen. Verify that second touch is only accepted near the first tap