On R and below, when an app that is not the active VPN app calls
getConnectionOwnerUid, a SecurityException is thrown. On S and
above, the method just returns INVALID_UID, which is what would
happen if the app was the active VPN app but was not authorized
to find that particular socket.
Accept both behaviours.
Bug: 173331190
Test: atest HostsideVpnTests#testGetConnectionOwnerUidSecurity passes on R and S
Change-Id: Ie6de2ef505b0d7bc253c55215a698aeaa210785c
98d23e7d02