Finish activity on top by CLEAR_TOP vs. sending broadcast

The test activity didn't finish due to the broadcast
was sent from an instant app while the CTS was running
in instant app mode.

Bug: 198102401
Test: atest ToastTest#testCustomToastBlocked_whenBehindTranslucentActivity

Change-Id: I0305590e77b7d8d2d505b302b5faf5c34d725525
(cherry picked from commit 75a42a40d3706e27cec757fdc98beb3f62734f89)
2 files changed