Fix omission of updates to child frames on Android

Fix omission of updates to child frames on Android

* java/org/gnu/emacs/EmacsView.java (onAttachedFromWindow):
Force a layout cycle rather than report exposure immediately.
(prepareForLayout): Delete function.

* java/org/gnu/emacs/EmacsWindow.java (mapWindow): Remove
redundant calls to prepareForLayout.

* src/androidterm.c (handle_one_android_event): Do not swap
buffers when exposure is registered by a frame only partially
updated.

(cherry picked from commit 73a58329a6946f5abc62fee2647efba56cce236b)