Remove tests related to LegacyVpnRunner. am: 879655c77b

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2727557

Change-Id: I9327f1c3eef82452d1ba858368fe74e79455fd8b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>