Add test cases of tunnel opened for EpdgTunnelManager am: e3c862242c

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/services/Iwlan/+/18493986

Change-Id: Idcf5f13b848aa854b19a971726676a901890ba39
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>