Update Android port

Update Android port

* java/org/gnu/emacs/EmacsInputConnection.java (beginBatchEdit)
(endBatchEdit, commitCompletion, commitText, deleteSurroundingText)
(finishComposingText, getSelectedText, getTextAfterCursor)
(getTextBeforeCursor, setComposingText, setComposingRegion)
(performEditorAction, performContextMenuAction, getExtractedText)
(setSelection, sendKeyEvent, deleteSurroundingTextInCodePoints)
(requestCursorUpdates): Ensure that the input connection is up
to date.
(getSurroundingText): New function.
* java/org/gnu/emacs/EmacsNative.java (getSurroundingText):
Export new C function.
* java/org/gnu/emacs/EmacsService.java (resetIC): Invalidate
previously created input connections.
* java/org/gnu/emacs/EmacsView.java (EmacsView)
(onCreateInputConnection): Signify that input connections are
now up to date.
* src/androidterm.c (struct
android_get_surrounding_text_context): New structure.
(android_get_surrounding_text, NATIVE_NAME):
* src/textconv.c (get_surrounding_text):
* src/textconv.h: New functions.