Make sure IME focus is synced to View focus

This CL fixes an edge case that my previous CL [1] forgot to handle.

The goal of my previous CL was to avoid InputMethodManager from getting
confused by a false focus-in event from temporarily detached Views.
However, my CL forgot to take care of the case where the temporarily
detached View is still focused even after the temporary detach mode is
done.

The bad news is that such a situation is relatively easy to trigger by
having a ListView that has EditText as follows, which seems to be
known to be a common technique in Android developer community to put an
EditText in a ListView.
  ListView#listView.addHeaderView(new EditText(context), null, true);

If the ListView is initialized as above, and the EditText has input
focus, View focus and IME focus start to disagree immediatelly after the
ListView's layout is re-evaluated.  This is really easy to trigger, for
example just by dismissing the IME window.

In summary, the root cause is that InputMethodManager#focusIn(View) is
now always ignored as long as the View is temporarily detached, under an
assumption that IMM#focusIn(View) will be called back again with a View
that is not temporarily detached when everything is stable.  Hence the
fix is to do so by hooking up View#dispatchFinishTemporaryDetach() to
call IMM#focusIn(View) again when the View is actually focused in the
final state.

 [1]: Ia79bbd8468f768d546354382b47b39dd31ef7bb5
      a4ed0cfcb6885beeb52f701bfc64c393b668f7ba

Bug: 30022872
Bug: 30578745
Bug: 30706985
Change-Id: Iecbdb00dcef8c72e4f7b31035c9bf0f4a40a578f
(cherry picked from commit dd228fbb4d2cb3d178ed7f1889343bfe177aafa2)
(cherry picked from commit 8eb07090a4fdd5a184f172853249323d85cff262)
1 file changed