Fixed get packages for HSUM devices

On HSUM devices, packages installed on secondary users can't
be retrieved by the system users' package manager. Fixed by
using corresponding user's package manager.

Fix: 356827794
Fix: 362253919
Test: Basic telephony functionality tests
Test: atest FrameworksTelephonyTests TeleServicesTests
Flag: com.android.internal.telephony.flags.hsum_broadcast
Change-Id: Ia1ce62dab3c46f9f048724850d66eab3c6542207