Update Permission only if the network is created

Reproduction steps:

- Register a NetworkAgent but don't mark it as connected.
- Set teardownDelayMs for the NetworkAgent to 100
- Unregister the NetworkAgent then see system crashed.

Tests:

- Builds, Boots
- ConnectivityServiceTest

Change-Id: Ib8e517acb0193a2454d672612fe61fc199de46a4
Bug: 200023207
1 file changed