APPSEC-1053 Validate S6648 ARM default value for secret (#3019)

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rules/S6648/azureresourcemanager/how-to-fix-it/bicep.adoc

@@ -15,5 +15,5 @@ param secureStringWithDefaultValue string = 'S3CR3T' // Noncompliant
 [source,bicep,diff-id=11,diff-type=compliant]
 ----
 @secure()
-param secureStringWithDefaultValue string
+param secureString string
 ----