making kind argument as enum instead of string

Author: khushishah513

src/containerapp/azext_containerapp/_params.py

@@ -31,7 +31,7 @@ def load_arguments(self, _):
         c.argument('revisions_mode', arg_type=get_enum_type(['single', 'multiple', 'labels']), help="The active revisions mode for the container app.")
 
     with self.argument_context('containerapp') as c:
-        c.argument('kind', type=str, help="Set to 'functionapp' to enable built-in support and autoscaling for Azure Functions on Azure Container Apps.", is_preview=True)
+        c.argument('kind', arg_type=get_enum_type(['functionapp']), help="Set to 'functionapp' to enable built-in support and autoscaling for Azure Functions on Azure Container Apps.", is_preview=True)
 
     with self.argument_context('containerapp create') as c:
         c.argument('source', help="Local directory path containing the application source and Dockerfile for building the container image. Preview: If no Dockerfile is present, a container image is generated using buildpacks. If Docker is not running or buildpacks cannot be used, Oryx will be used to generate the image. See the supported Oryx runtimes here: https://aka.ms/SourceToCloudSupportedVersions.", is_preview=True)