title: AWS CloudFormation Error 'Value of property AlarmActions must be of type List of String'
body: <p>i am trying to update my cf stack and encounter the following error on deploy:
  'Value of property AlarmActions must be of type List of String'</p>
  
  <p>this is the property AlarmActions:</p>
  
  <pre><code> AlarmActions:
                  - !Ref SparksTeamSNSTopic
                  - !If
                      - CreateProdResources
                      - - !Ref SparksProdAlarmSNSTopic
                        - !ImportValue
                            'Fn::Sub': '${Environment}-BMCMajorAlarmTopic'
                      - - !Ref 'AWS::NoValue'                   
  </code></pre>