Fix reset permissions on clear data and package uninstall.

If the user clears data for an app we reset the permission but
only the changes made by the user. We do not modify syste or
policy flags and also ensure the permission that were granted
by default are granted after the data wipe. This is the same
as starting with a clean slate.

If the package whose data is cleared is a part of a shared user
we resent to initial state only the permissions that the cleared
package contributed. Hence, if another package also declared the
permission as used we do not clear the permission state as it is
still in use.

When a package is deleted for a user but still present for another
user we reset its permissions to their inital state follwoing
above described strategy.

Lastly when a preinstalled package wtih an upgrade is diabled
(triggers upgrade uninstall) and this package is a part of a
shared user, we do not drop permission state (grants and flags)
for permissions used by the shadowed system package. This ensures
that we do not drop runtime permission state (such state is
default grants and user changes).i

bug:22248525

Change-Id: I3a3007476d2cb9f4ff824e1e137a6e1a4d04408b