veyron/runtimes/google/ipc: make ipc.TestServerStatus test more robust
veyron/runtimes/google/ipc: make ipc.TestServerStatus test more robust

The ipc.TestServerStatus test fails intermittently because the test
for ServerStopped sometimes detects ServerStopping so try a few extra
times for ServerStopped state to be reached.

Change-Id: Idd7022013d41eeab76f2e4c402c356296a699ef0

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref