Adding tags to the azure_rm_appgateway module. (#1373)

* Adding tags to the azure_rm_appgateway module.

* Removing unnecessary tags from module_arg_spec.

* Separate conditional for tag update.

* Missing parenthesis.

* Moving conditional under another.

plugins/modules/azure_rm_appgateway.py

@@ -2239,6 +2239,8 @@ def exec_module(self, **kwargs):
                     self.parameters["web_application_firewall_configuration"] = kwargs[key]
                 elif key == "enable_http2":
                     self.parameters["enable_http2"] = kwargs[key]
+                elif key == "tags":
+                    self.parameters["tags"] = kwargs[key]
 
         response = None
 
@@ -2296,6 +2298,11 @@ def exec_module(self, **kwargs):
             else:
                 self.to_do = Actions.NoAction
 
+            update_tags, new_tags = self.update_tags(old_response['tags'])
+            if update_tags:
+                self.to_do = Actions.Update
+                self.parameters["tags"] = new_tags
+
         if (self.to_do == Actions.Create) or (self.to_do == Actions.Update):
             self.log("Need to Create / Update the Application Gateway instance")