Description of problem:

 Cluster storage operator credentials request for AWS does not include KMS statements. This leads to failure to deploy PVs due to inability to provide a key.

Version-Release number of selected component (if applicable):

 Tested on 4.9.12.

How reproducible:

 Always

Steps to Reproduce:
1. Install to restricted AWS environment with out KMS privileges by default
2. Create IAM roles with ccoctl from credentials requests
3. Create pvc in gp2-csi storage class (same problem, deiff error in gp2 SC)

        cat <<EOF | oc create -n $PROJ -f -
        apiVersion: v1
        kind: PersistentVolumeClaim
        metadata:
          name: data-csi
        spec:
          storageClassName: "gp2-csi"
          resources:
            requests:
              storage: 512Mi
          accessModes:
            - ReadWriteOnce
        EOF
        oc set volume -n $PROJ deployment/demo --add -m /opt/app-root/src/data \
                --name=data -t persistentVolumeClaim --claim-name=data-csi
        oc describe pvc data-csi -n $PROJ

Actual results:

 PVC in gp2-csi class results in:

    Events:
      Type     Reason                Age                From                                                                     Message
      ----     ------                ----               ----                                                                     -------
      Normal   WaitForFirstConsumer  27s (x3 over 57s)  persistentvolume-controller                                              waiting for first consumer to be created before binding
      Warning  ProvisioningFailed    15s                ebs.csi.aws.com_ip-100-127-136-183_16213ddf-eedf-480a-84ed-116b1df1caa6  failed to provision volume with StorageClass "gp2-csi": rpc error: code = Internal desc = Could not create volume "pvc-eeb59df1-f744-46e9-b0c4-288f3c8d1bc1": failed to get an available volume in EC2: InvalidVolume.NotFound: The volume 'vol-0c94abf5d9bfe6680' does not exist.
               status code: 400, request id: 3c39958c-353a-48c2-bc75-37bd04673718
      Normal   ExternalProvisioning  12s (x2 over 19s)  persistentvolume-controller                                              waiting for a volume to be created, either by external provisioner "ebs.csi.aws.com" or manually created by system administrator
      Normal   Provisioning          8s (x4 over 19s)   ebs.csi.aws.com_ip-100-127-136-183_16213ddf-eedf-480a-84ed-116b1df1caa6  External provisioner is provisioning volume for claim "dale/data-1150"
      Warning  ProvisioningFailed    7s (x3 over 14s)   ebs.csi.aws.com_ip-100-127-136-183_16213ddf-eedf-480a-84ed-116b1df1caa6  failed to provision volume with StorageClass "gp2-csi": rpc error: code = AlreadyExists desc = Could not create volume "pvc-eeb59df1-f744-46e9-b0c4-288f3c8d1bc1": Parameters on this idempotent request are inconsistent with parameters used in previous request(s)


 PVC in the gp2 class (using the in-tree driver) results in error providing clue to cause of failure above:

        Events:
          Type     Reason                Age                From                         Message
          ----     ------                ----               ----                         -------
          Normal   WaitForFirstConsumer  13s (x3 over 41s)  persistentvolume-controller  waiting for first consumer to be created before binding
          Warning  ProvisioningFailed    6s                 persistentvolume-controller  Failed to provision volume with StorageClass "gp2": failed to create encrypted volume: the volume disappeared after creation, most likely due to inaccessible KMS encryption key
          Normal   WaitForPodScheduled   6s                 persistentvolume-controller  waiting for pod demo-5c75b5598f-gvpvv to be scheduled


Expected results:

 PV created and PVC bound.

 After adding to following policy statement to the IAM role used by csi operator pod:

        {
            "Sid": "AddKMS0",
            "Effect": "Allow",
            "Action": [
                "kms:Decrypt",
                "kms:Encrypt",
                "kms:GenerateDataKey",
                "kms:GenerateDataKeyWithoutPlainText",
                "kms:DescribeKey"
            ],
            "Resource": "*"
        }

 PVC binds properly:

    Events:
      Type    Reason                 Age                From                                                                     Message
      ----    ------                 ----               ----                                                                     -------
      Normal  WaitForFirstConsumer   31s (x4 over 65s)  persistentvolume-controller                                              waiting for first consumer to be created before binding
      Normal  Provisioning           17s                ebs.csi.aws.com_ip-100-127-136-183_16213ddf-eedf-480a-84ed-116b1df1caa6  External provisioner is provisioning volume for claim "dale/data-1147"
      Normal  ExternalProvisioning   16s (x3 over 17s)  persistentvolume-controller                                              waiting for a volume to be created, either by external provisioner "ebs.csi.aws.com" or manually created by system administrator
      Normal  ProvisioningSucceeded  14s                ebs.csi.aws.com_ip-100-127-136-183_16213ddf-eedf-480a-84ed-116b1df1caa6  Successfully provisioned volume pvc-81ea5b8e-bbe9-4d10-9fc4-452a58e66d79


Additional info:

 The credentials request lacks any KMS actions.
 https://github.com/openshift/cluster-storage-operator/blob/master/manifests/03_credentials_request_aws.yaml#L20

 Contrast this to machine API which uses KMS for boot disk encryption.
 https://github.com/openshift/machine-api-operator/blob/master/install/0000_30_machine-api-operator_00_credentials-request.yaml#L45-L58