Prevent Fullscreen IME when app is in portrait.

When an app is running in portrait orientation, regardless of
what orientation display is in, IME shouldn't use fullscreen-mode.

Setting IME_FLAG_NO_FULLSCREEN in EditorInfo makes sure IME doesn't go
fullscreen.

Bug: 157870379
Test: Manually using steps in bug
Change-Id: I5a5e73e1dec776665f28a7e2eb091b555198001b