Fix IME hide state

Insets API notifies IME when it's hidden. however, IMMS never
really received these state changes. Using requestHideSelf() makes sure
IMMS is in-sync.

Fix: 151980214
Test: manually using the steps in bug

Change-Id: I7f6098a61a5942795ffd33a60329e4dd5fb5d6cb
1 file changed