replace clean_image_name with clean_resource_name

The change was mostly made except in one example for Google

website/pages/docs/templates/engine.mdx

@@ -173,7 +173,7 @@ Here is a full list of the available functions for reference.
   This engine does not guarantee that the final image name will match the
   regex; it will not truncate your name if it exceeds 63 characters, and it
   will not validate that the beginning and end of the engine's output are
-  valid. For example, `"image_name": {{isotime | clean_image_name}}"` will
+  valid. For example, `"image_name": {{isotime | clean_resource_name}}"` will
   cause your build to fail because the image name will start with a number,
   which is why in the above example we prepend the isotime with "mybuild".