Use the current user to check appops against

There is no need to do cross user checks here; all that is needed is
for the packages to be installed across users.

Flag: TEST_ONLY
Fixes: 377385365
Test: AppOpsMultiUserTest, also reverted the platform fix locally to
          ensure the test is still verifying what it needs to.
Change-Id: Iff1552bd2f22ba8cb2a0aef9beaa179069e2cb4b