Add ability to vm library to retry until we can ssh into it.

bin/cros_run_vm_test

Index: bin/cros_run_vm_test
diff --git a/bin/cros_run_vm_test b/bin/cros_run_vm_test
index ee86879c7820c8c0dadb664cde2b77b7c0a688aa..9e3bba7170c59ba62f03e2e46fd6d63c3c28a633 100755
--- a/bin/cros_run_vm_test
+++ b/bin/cros_run_vm_test
@@ -10,6 +10,8 @@
 . "$(dirname $0)/../lib/cros_vm_lib.sh"
 . "$(dirname "$0")/../lib/cros_vm_constants.sh"
 
+MAX_RETRIES=3
+
 DEFINE_string image_path "" "Full path of the VM image"
 DEFINE_string test_case "" "Name of the test case to run"
 
@@ -32,6 +34,8 @@ fi
 
 trap stop_kvm EXIT
 start_kvm "${FLAGS_image_path}"
+info "Checking for ssh access to virtual machine."
+retry_until_ssh ${MAX_RETRIES}
 "$(dirname $0)"/../run_remote_tests.sh \
   --ssh_port=${FLAGS_ssh_port} \
   --remote=127.0.0.1 \