Fix NPE in NetworkPolicyLogger.networkBlocked().

Fixes: 203822380
Test: atest cts/hostsidetests/net/src/com/android/cts/net/HostsideRestrictBackgroundNetworkTests.java
Change-Id: Ibe5340caf6a7f6b1457c9230e34607cf293f39f3
Merged-In: Ibe5340caf6a7f6b1457c9230e34607cf293f39f3
1 file changed