Only use the IME target from IMMS to update the IME control target

DisplayContent.mInputMethodTarget is only used for deciding which window
IME should attach to.

Fix: 152698568
Fix: 153287963
Test: Steps in the bugs.
Change-Id: Ife6b700436ffa6ce80af9c6c276c0fcf3a4e057a
(cherry picked from commit 304db431533085708d376aa5d1e5292f9a6870b2)
1 file changed