Fix deadlock when updating rotation

Post a runnable in MyOrientationListener.onProposedRotationChanged for
the updateRotation() so that it doesn't acquire WM lock while holding
WindowOrientationListener lock. It could cause deadlock if WM is
is performing a relayout and try to access WindowOrientationListener.

bug: 23507268
Change-Id: I5775f5a13cae0283fef64877801bf8a39dfc90a4