Update Android port

Update Android port

* java/org/gnu/emacs/EmacsInputConnection.java
(EmacsInputConnection, beginBatchEdit, reset, endBatchEdit):
Keep track of the number of batch edits and return an
appropriate value.
(takeSnapshot): Implement function.
* java/org/gnu/emacs/EmacsNative.java (takeSnapshot): New
function.
* java/org/gnu/emacs/EmacsService.java (resetIC): Improve
debugging output.
* java/org/gnu/emacs/EmacsView.java (onCreateInputConnection):
Call `reset' to clear the UI side batch edit count.
* src/androidterm.c (struct
android_get_surrounding_text_context): New fields
`conversion_start' and `conversion_end'.
(android_get_surrounding_text): Return the conversion region.
(android_get_surrounding_text_internal, NATIVE_NAME): Factor out
`getSurroundingText'.
(takeSnapshot): New function.