Fix manifest.yaml - Parameter pNISTStandardVersion must be one of AllowedValues (#198)

With this version of the manifest.yaml appears the following error: 

"Parameter 'pNISTStandardVersion' must be one of AllowedValues"

The default value is "false" and the AllowedValues: [5.0.0]

Author: alazaroc

Diff for: aws_sra_examples/easy_setup/customizations_for_aws_control_tower/manifest.yaml

@@ -232,7 +232,7 @@ resources:
       - parameter_key: pEnableNISTStandard
         parameter_value: 'false'
       - parameter_key: pNISTStandardVersion
-        parameter_value: 'false'
+        parameter_value: '5.0.0'
       - parameter_key: pRegionLinkingMode
         parameter_value: 'SPECIFIED_REGIONS'