Refactor VTI tests to support null encryption

-Split input and output into separate tests
-Refactor to inject null encrypted packets while still allowing
 encrypted packets to be mirrored
-Add a check to ensure plaintext packets are not sent.

Bug: 66467511
Test: this
Change-Id: I6cad55f65d32fae9ea17fb44ea796bdcd4aba3a3
1 file changed
tree: 3c76fc5f6f5f467017fdc0e1ade67cc6b7f9010e
  1. devicetree/
  2. net/
  3. Android.bp