Filter out user handle in ST package check

Only the app id part of uid matters in checking against the uid
associated with a package from package manager.

Bug: 281778398
Test: agsa/as smoke + user switch tests
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:c253a493d3ace0eb7baefe8f5c37a4c9da07d400)
Merged-In: I8e00f95c5e2d756ef256828d6360c9f7e3226c10
Change-Id: I8e00f95c5e2d756ef256828d6360c9f7e3226c10