crypto/tls: add timeouts to recorded tests

crypto/tls: add timeouts to recorded tests

If something causes the recorded tests to deviate from the expected
flows, they might wait forever for data that is not coming. Add a short
timeout, after which a useful error message is shown.

Change-Id: Ib11ccc0e17dcb8b2180493556017275678abbb08
Reviewed-on: https://go-review.googlesource.com/c/144116
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Adam Langley <agl@golang.org>