Refactor VPN interface filtering necessity check

Bug: 206482423
Test: atest ConnectivityServiceTest
Change-Id: Iedf344f6275d4c6b23716eb11e3eecf54c6a2f9a
(cherry picked from commit 77a794868fd478dadb90e5e1fa71debd7257db4d)
Merged-In: Iedf344f6275d4c6b23716eb11e3eecf54c6a2f9a
1 file changed