Fix NetworkPolicyManager unit tests.

Bug: 137859686
Test: atest core/tests/coretests/src/android/net/NetworkPolicyManagerTest.java
Test: atest services/tests/servicestests/src/com/android/server/net/NetworkPolicyManagerServiceTest.java
Change-Id: I38a935c71bfb1f78739d508b400e43dc1b52bef5
Merged-In: I38a935c71bfb1f78739d508b400e43dc1b52bef5
(cherry picked from commit 6ec3caf21811ce40e188b7a43c744c0057cd54af)
3 files changed