Update Android port

Update Android port

* doc/lispref/commands.texi (Touchscreen Events): Improve
documentation.
* lisp/tab-bar.el (tab-bar-map): Bind `[tab-bar
touchscreen-hold]'.
* lisp/touch-screen.el (touch-screen-hold, touch-screen-drag):
New functions.
(touch-screen-handle-timeout): Generate a `touchscreen-hold'
event instead.
(touch-screen-handle-point-update): Generate a
`touchscreen-drag' event upon dragging.
(touch-screen-translate-touch): Cancel touch screen timer upon
exit.
* src/keyboard.c (access_keymap_keyremap): Take unsigned int
start and end instead.