Revert "Block background custom toasts"

This reverts commit 880cf32c707bfe3cac49189b0d9e118441cd52ab.

Reason for revert: Broke CtsWindowManagerDeviceTestCases ToastTest.testToastIsNotClickable()

Change-Id: Ia108eeee81b673306d0e552e01d18e1558a00dd8
4 files changed