Fix NPE if themeContext is null - round 2

If a theme is uninstalled and timing is perfect, it can happen
that the CopyImageService is trying to get the PackageContext
of a not existing package.

Return from the function if a NameNotFoundException is catched.

Change-Id: I8f4e33d527f78228f9681ac518292364e9269a0c
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Listen for ACTION_PACKAGE_BEING_REMOVED

Requires http://review.cyanogenmod.org/#/c/64139/

This will allow us to handle changing back to the default
theme for any components that are using the package about
to be removed.  Some apps may crash if the them resources are
removed before we change the theme back.

Change-Id: If1778ea4dd3be86af21479f12e75d22083e168ef