autofill: support dpad/keyboard

To make autofill works on non-touch device such as TV, allow
fill ui window to gain window focus. Fill ui window does not
need IME. When IME and fill ui window are both shown, fill ui
window will intercept keyevent before IME.

Since autofill window will steal window focus from app window,
we no longer uses View.onWindowFocused() for enter/exit event.
Switched to use Activity onResume/onPause. When view
notifyViewEntered or notifyViewExited called when Activity is paused,
it will be ignored. Before Activity goes to pause state,
notifyViewExited() is fired on focus view, after Activity leaves
pause state, notifyViewEntered() is fired on focus view.

In CTS testDatasetAuthTwoFieldsUserCancelsFirstAttempt,  the
authentication activity finishes itself in onCreate() which will not
produce onPause/onResume in app activity, but it will produce window
focus loss/gain event. Since we switch from window focus to activity
onResume/onPause, we will be missing a show fill ui when return from
the never shown authentication activity. To solve this problem,
we added special code when receive ActivityResult from authentication
activity where we check if the authenticate activity never causes
onStop event, where we should issue an extra ACTION_VIEW_ENTERED
event to show fill ui.

Test: passed all existing autofilltest CTS on sailfish
      atest CtsAutoFillServiceTestCases
Bug: 70181616

Change-Id: Iafe4dca3be8f049fa6dfd34bac13ccb030c583b6