KMS Encryption Customer Master Key (CMK) with Automatic Key Rotation

AWSTemplateFormatVersion: '2010-09-09'
Description: ''
Resources:
  KMSKey:
    Type: 'AWS::KMS::Key'
    Properties:
      EnableKeyRotation: true
      KeyPolicy:
        Version: '2012-10-17'
        Statement:
          - Sid: Enable IAM User Permissions
            Effect: Allow
            Principal:
              AWS:
                'Fn::Join':
                  - ''
                  - - 'arn:aws:iam::'
                    - Ref: 'AWS::AccountId'
                    - ':root'
            Action: 'kms:*'
            Resource: '*'
Parameters: {}
Metadata: {}
Conditions: {}