Add CTS tests for nearby notification streaming policy

Bug: 183617761
Test: atest DevicePolicyManagerTest
Test: atest
MixedManagedProfileOwnerTest#testGetNearbyNotificationStreamingPolicy
Test: atest
MixedManagedProfileOwnerTest#testSetNearbyNotificationStreamingPolicy

Change-Id: I3da0cfc57d9a6be71a655e9de6ffdf47df62380e
3 files changed