Add per UID control to app ops.

The app ops mananger service maintains a mapping from UID to
a list of packages where each package is mapped to a list of
non-default app op states (default states are inferred and
not stored). Hence, specifying the app op state for a UID
requires setting the app op for each package in the shared
UID.

This is problematic when installing new packages if there
is a non-default app op policy set for another already
installed package in the same UID as the app op for the new
package has to be updated to be in sync. The package installer
cannot do this as it is in another process and the app op
update will not be atomic. Therefore, the app ops manager
service has to support specifying app op policy on a per
UID basis.

We now have a UID state object that contains the per package
non-default app op states as well as the per uid non-default
app op states. If there is a UID policy specified then it
takes precedence over the per package one. Even further,
changing the uid policy updates the package policies in this
UID if the state is non-default. Changing a package app op
state also updates the app op state for the whole UID if
the per UID policy for this op is non-default. Clearing the
app op state for a package, clears the policy for the UID
as well.

bug:22802981

Change-Id: I78044906d9fcc6066abf07e706c2c88f3397d293