IME Framework CTS: add broadcast barrier after installing test apps.

Fixes an issue where delayed PACKAGE_ADDED broadcasts about the MockIme
cause InputMethodManagerService not to know about the MockIme during the
first few tests.

Bug: 263784839
Fixes: 268159472
Change-Id: Id9c56a8137e7e74b4cbaad7eb78ab7f288f24484
Merged-In: Id9c56a8137e7e74b4cbaad7eb78ab7f288f24484
Test: atest CtsInputMethodTestCases
(cherry picked from commit 80199a899b24404b11565c22d6d3979ebcc6b00b)
2 files changed