android: lcd_update/_rect() changes

* rename some java methods (to update(), initialize())
* re-create the ByteBuffer object from the framebuffer on every update.
  This is needed now since 2c71aa9 added the possiblity for lcd_framebuffer to change.
* do so, along with the creation of the dirty Rect object, in native code.

Change-Id: Id39ea8e4b6148987c5f216a87e0ff3c8e7babe92
2 files changed