This CL adds tests to verify that after setting
IpSecTunnelInterface to use a different undelying network and
re-applying IpSecTransforms with matching addresses, traffic
can be routed to/from the new underlying network.
All these new tests will be skipped if SDK < S
Bug: 169855650
Test: atest IpSecManagerTunnelTest (new tests added)
Original-Change: https://android-review.googlesource.com/1488296
Merged-In: Iab26159e5e070574e552d62e4f0780059a51a9c7
Change-Id: Iab26159e5e070574e552d62e4f0780059a51a9c7
0271dc24ce