Change packageInfo observe conditions

Change under what conditions the LightPackageInfoLiveData observe the
UserPackageInfosLiveData. Also enusure that the first time UID is set,
that a permission listener is registered.

Fixes: 157661464
Test: Go to the permissions UI, and grant/revoke several apps on the
same page. They should be consistent

Change-Id: I5639c025c4f2c80adfaae904fe090bd5ca929828