Initial CL for testing IkeSession creation

This commit:
-Extend TunUtils for processing IKE packets
-Add IkeSessionBaseTest containing common functionality for all IkeSession tests
-Add end-to-end test for IKEv2 PSK verifying creating IKE SA, creating child SAs
 and closing sessions
-Add basic tests for error scenarios

Bug: 148689509
Test: atest CtsIkeTestCases
Change-Id: Ie6c18591ffcc883abbf0484d9a59dfda61b33257
8 files changed
tree: 3d089cf2e651329cd07b842af196353099ebf08a
  1. tests/