Add more aggressive DTLS replay tests.

The existing tests only went monotonic. Allow an arbitrary mapping
function. Also test by sending more app data. The handshake is fairly
resilient to replayed packets, whereas our test code intentionally
isn't.

Change-Id: I0fb74bbacc260c65ec5f6a1ca8f3cb23b4192855
Reviewed-on: https://boringssl-review.googlesource.com/5556
Reviewed-by: Adam Langley <agl@google.com>
4 files changed