Fail to create agents with GPU attached from Machine Configuration in Jenkins settings UI. Instances with guest accelerators do not support live migration.

Hello, it seems that it is possible to create GPU agent by specifying instance template for creating instances. But it is not possible to create GPU agent without specifying instance template. See related issue https://issues.jenkins-ci.org/browse/JENKINS-52708.

As workaround you can use following https://github.com/dkozlov/google-compute-engine-plugin/commit/7b7af84ee0a2cf177b2f9be8e65c656f45d964a4

Could you please disable GPU support in Machine configuration UI or fix it

```Apr 08, 2019 5:23:23 AM INFO com.google.jenkins.plugins.computeengine.ComputeEngineCloud provision

Provisioning node from config com.google.jenkins.plugins.computeengine.InstanceConfiguration@3bafb6a8 for excess workload of 1 units of label 'jenkins-gpu'

Apr 08, 2019 5:23:23 AM INFO com.google.jenkins.plugins.computeengine.ComputeEngineCloud availableNodeCapacity

Found capacity for 99 nodes in cloud

Apr 08, 2019 5:23:24 AM WARNING com.google.jenkins.plugins.computeengine.ComputeEngineCloud provision

Error provisioning node
com.google.api.client.googleapis.json.GoogleJsonResponseException: 400 Bad Request
{
"code" : 400,
"errors" : [ {
"domain" : "global",
"message" : "Instances with guest accelerators do not support live migration.",
"reason" : "badRequest"
} ],
"message" : "Instances with guest accelerators do not support live migration."
}
at com.google.api.client.googleapis.json.GoogleJsonResponseException.from(GoogleJsonResponseException.java:146)
at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:113)
at com.google.api.client.googleapis.services.json.AbstractGoogleJsonClientRequest.newExceptionOnError(AbstractGoogleJsonClientRequest.java:40)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest$1.interceptResponse(AbstractGoogleClientRequest.java:321)
at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:1067)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:419)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:352)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:469)
at com.google.jenkins.plugins.computeengine.client.ComputeClient.insertInstance(ComputeClient.java:374)
at com.google.jenkins.plugins.computeengine.InstanceConfiguration.provision(InstanceConfiguration.java:319)
at com.google.jenkins.plugins.computeengine.ComputeEngineCloud.provision(ComputeEngineCloud.java:203)
at hudson.slaves.NodeProvisioner$StandardStrategyImpl.apply(NodeProvisioner.java:715)
at hudson.slaves.NodeProvisioner.update(NodeProvisioner.java:320)
at hudson.slaves.NodeProvisioner.access$000(NodeProvisioner.java:62)
at hudson.slaves.NodeProvisioner$NodeProvisionerInvoker.doRun(NodeProvisioner.java:809)
at hudson.triggers.SafeTimerTask.run(SafeTimerTask.java:72)
at jenkins.security.ImpersonatingScheduledExecutorService$1.run(ImpersonatingScheduledExecutorService.java:58)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)

```