Remove the current input focused window when ANR

When a freeform app launched and focused, but its window is not ready,
the input focus stays on the window of the previously focused freeform
app. The focus should be removed from the previously foccused app, so
ANR can be triggered correctly.

Bug: 216852742
Test: atest AnrTests#slowOnCreateWithKeyEventTriggersAnr
Change-Id: Id00c147ffab9b11fb2abdf0f3020bc017a31bea7