DO NOT MERGE: Introduce DPMS shim for active DO/PO check

Introduce a shim into DevicePolicyManagerInternal &
DevicePolicyManagerService so that NetworkStatsAccessTest would not
diverge from internal development branches.

The DevicePolicyManagerService refactoring on the internal branch
removed isActiveAdminWithPolicy in favour of isActiveDeviceOwner and
isActiveProfileOwner.

These methods are being made available in AOSP for
NetworkStatsAccessTest.

Bug: 170459325
Test: atest NetworkStatsAccessTest
Change-Id: Ic7e0898989fb8222aaba2b35436765c04eb3250c