What to do when json field conflicts with Splunk metadata?

[pkeller]

A user is reporting that their indexed json data has a 'source' key that is being extracted.

"source": "[{label:'Tree'},{label:'two'},{label:'Three'}]",

When they search their data, they see:

They'd like the original source kept intact. Is there a transforms that I can add to my indexers to rename ONLY the json source?

The raw json looks like: [ snipped ]

"toggleMode":"click",
"_toggleMode": {
"desc": "Gets or sets user interaction used for expanding or collapsing any item.",
"type": "enum",
"keys": ["click","dblclick"],
"values": ["click","dblclick"]
},
*"source": "[{label:'Tree'},{label:'two'},{label:'Three'}]",**
"_source": {
"desc": "Sets the initial contents. Easier to do at runtime.",
"type": "css",
"language": "JavaScript"
},*

[GauravSplunxter]

transforms.conf
[change_source]
REGEX = "source":\s"[(\S+)]
FORMAT = source::$1
DEST_KEY = MetaData:Source