Fix issue #5680541: onStartInputView called upon focus loss

We should tell the app that it is inactive, before unbinding.
Otherwise when it is told to unbind it will see that it is still
supposed to be active and immediately re-bind.

Also change the calls to set the active state to go through the
message dispatch path, to ensure ordering is correct.

Change-Id: I246241eac8f7521f42c4c1eee7f46097337e7303