vmm_tests/cvm: workaround windows guest bug on hvsock revoke

[chris-oo]

On a hvsock revoke in a CVM, a windows guest will bugcheck due to a bug in the vmbus driver. Until a windows fix is rolled out to public images, figure out a way to workaround this so the tests don't appear flakey in ci.

[chris-oo]

Some ideas from Trevor include increasing the timeout for connect, or waiting for a heartbeat ic before we then attempt to connect.