1. If a print service does not export its activities for settings and
adding printers the print spooler ignores them instead of crashing.
Also if the service is not enabled its activities are now ignored.
2. Added a dedicated permission for a print service to optionally
protect its settings and add printer activities such that only the
system can bind to them.
3. Fixed a crash in the print dialog if its content is detached
from the window and animators are running.
bug:10680224
Change-Id: I20b57d6622a15f9b2352ba78d04c44e67b316a15
860f8a6b66