Window management files on the client side have normally been dumped in
either android.view or android.app package. This CL starts to
centralized them in android.window package so there is better
separation.
Test: they pass
Bug: 147406652
Bug: 152113464
Bug: 152117221
Change-Id: I4d64bd256e9b3581af0ccf9396f7dd2454132719
