I have a Spark Operator deployed to GKE using the Helm Chart. And there is a spark-pi.yaml that I've loaded to Google Storage. When I execute kubectl apply -f https://storage.cloud.google.com/my-bucket/spark-pi.yaml I'm getting the following error:

error converting YAML to JSON: yaml: line 11: mapping values are not allowed in this context

I've checked the file contents with an online YAML validator and it appears to be valid. I took the configuration from GoogleCloudPlatform/spark-on-k8s-operator examples.

The mainClass on line 11 is exactly the same as in the User guide.

What may be wrong with the file and how can I fix it?

spark-pi.yaml

apiVersion: "sparkoperator.k8s.io/v1beta2"
kind: SparkApplication
metadata:
  name: spark-pi
  namespace: default
spec:
  type: Scala
  mode: cluster
  image: "gcr.io/spark-operator/spark:v2.4.5"
  imagePullPolicy: Always
  mainClass: org.apache.spark.examples.SparkPi
  mainApplicationFile: "local:///opt/spark/examples/jars/spark-examples_2.11-2.4.5.jar"
  sparkVersion: "2.4.5"
  restartPolicy:
    type: Never
  volumes:
    - name: "test-volume"
      hostPath:
        path: "/tmp"
        type: Directory
  driver:
    cores: 1
    coreLimit: "1200m"
    memory: "512m"
    labels:
      version: 2.4.5
    serviceAccount: default
    volumeMounts:
      - name: "test-volume"
        mountPath: "/tmp"
  executor:
    cores: 1
    instances: 1
    memory: "512m"
    labels:
      version: 2.4.5
    volumeMounts:
      - name: "test-volume"
        mountPath: "/tmp"