Fix appwidgets not updating

Previously there was a bug where if an appwidget's update caused a
TransactionTooLargeException then the AppWidgetServiceImpl.Host's
callbacks were completely disabled, for all widgets.

The fix still allows a DeadObjectException or other RemoteException
to disable the host callbacks, as that would be caused by a bad host.

Fixes issue 28216 on the public tracker
https://code.google.com/p/android/issues/detail?id=28216

Change-Id: I5c5d5939d7211ed23cca69e6674de730b51b0f3e
Signed-off-by: Kevin Barry <kevin@teslacoilsw.com>