Update Android port

Update Android port

* doc/emacs/android.texi (Android Startup, Android File System)
(Android Environment, Android Windowing, Android
Troubleshooting): Improve documentation; fix typos.
* doc/lispref/commands.texi (Misc Events): Likewise.
* java/org/gnu/emacs/EmacsService.java (queryBattery): New
function.
* lisp/battery.el (battery-status-function): Set appropriately
for Android.
(battery-android): New function.
* src/android.c (struct android_emacs_service): New method
`query_battery'.
(android_check_content_access): Improve exception checking.
(android_init_emacs_service): Look up new method.
(android_destroy_handle, android_create_window)
(android_init_android_rect_class, android_init_emacs_gc_class)
(android_set_clip_rectangles)
(android_create_pixmap_from_bitmap_data, android_fill_polygon)
(android_get_image, android_put_image, android_bell)
(android_set_input_focus, android_raise_window)
(android_lower_window, android_query_tree, android_get_geometry)
(android_translate_coordinates, android_wc_lookup_string)
(android_damage_window, android_build_string)
(android_build_jstring, android_exception_check_1)
(android_exception_check_2): New functions.
(android_browse_url): Improve exception handling.  Always use
android_exception_check and don't leak local refs.
(android_query_battery): New function.
* src/android.h (struct android_battery_state): New struct.
* src/androidfns.c (Fandroid_query_battery, syms_of_androidfns):
New function.
* src/androidfont.c (androidfont_from_lisp, DO_SYMBOL_FIELD)
(DO_CARDINAL_FIELD, androidfont_list, androidfont_match)
(androidfont_draw, androidfont_open_font)
(androidfont_close_font):
* src/androidselect.c (Fandroid_set_clipboard)
(Fandroid_get_clipboard):
* src/sfnt.c (sfnt_map_glyf_table):
* src/sfntfont.c (sfntfont_free_outline_cache)
(sfntfont_free_raster_cache, sfntfont_close): Allow font close
functions to be called twice.