Add annotation for Vpn#getNetwork()

- Add @VisibleForTesting & @Nullable for Vpn#getNetwork().
- Remove null check in caller side(test) of Vpn#getNetwork()
because if the code is working properly, it can never be null.

Bug: 182963397
Test: atest FrameworksNetTests
Change-Id: Ic52864003fbebd9f4e95d43fefc2e168437b0122
Merged-In: Ic52864003fbebd9f4e95d43fefc2e168437b0122
  (cherry-picked from ag/13946573)
1 file changed
tree: b1f0dc438e716e5d2b71ae47c446f8ca09462f21
  1. core/
  2. framework/
  3. service/
  4. services/
  5. tests/
  6. OWNERS
  7. TEST_MAPPING