Fix NPE in AppsFilter

Previously we used pmInternal to get shared user packages from package
setting. This has two issues:

1) pmInternal is null in the snapshotted version of AppsFilter which
   leads to NPE and system crashes.
2) The pmInternal method uses the snapshotted computer which means we
   are mixing live data (from mStateProvider) and snapshot data.

This CL fixes it by including all the share user packages info in the
StateProvider and force using live data for getting the shared user
packages.

BUG: 226668722
Test: atest AppsFilterImplTest
Change-Id: I5580e24382e4a1b9d3e41821def714af0899b822