allowing leaf key rewrites that aren't dcits (#3730)

Author: SteveMacenski

nav2_common/nav2_common/launch/rewritten_yaml.py

@@ -136,11 +136,13 @@ def updateYamlPathVals(self, yaml, yaml_key_list, rewrite_val):
 
     def substitute_keys(self, yaml, key_rewrites):
         if len(key_rewrites) != 0:
-            for key, val in yaml.items():
-                if isinstance(val, dict) and key in key_rewrites:
+            for key in list(yaml.keys()):
+                val = yaml[key]
+                if key in key_rewrites:
                     new_key = key_rewrites[key]
                     yaml[new_key] = yaml[key]
                     del yaml[key]
+                if isinstance(val, dict):
                     self.substitute_keys(val, key_rewrites)
 
     def getYamlLeafKeys(self, yamlData):