[ADI][12/N] fix multi-user verification policy on HSUM

On HSUM devices, both the main user and the system user are created at the very beginning of the boot, so they should be both assigned the default verification policy at that time. Otherwise, the main user won't have a policy and the user won't be able to change it either.

FLAG: android.content.pm.verification_service

BUG: 378377810
FIXES: 378377810
Test: create a gcar emulator and run CtsPackageManagerTestCases:android.content.pm.cts.VerifierServiceTest

Merged-In: I2f3f34fa4a6202e7bc3b6f0cbb31312f344ad9cd
Change-Id: I2f3f34fa4a6202e7bc3b6f0cbb31312f344ad9cd