IpSecManagerTest: Increase time to wait for packets

"Not enough traffic was recorded to satisfy the provided conditions" is
a commonly seen flake. This change increases the timeout value
arbitrarily to hopefully fix some of those failures.

I have not looked at the test in detail, so it is entirely possible that
this will not fix anything.

Test: TH
Bug: 270135449
Change-Id: I31b14c560c21f2942a87b88e75e5aca0a3b1c270
1 file changed