Modifying the builtin Windows runtime to send the exited event
immediately upon the container's init process exiting, without first
waiting for the Compute System to shut down, perturbed the timings
enough to make TestWaitConditions flaky on that platform. Make
TestWaitConditions timing-independent by having the container wait
for input on STDIN before exiting.
Signed-off-by: Cory Snider <csnider@mirantis.com>