Apache Druid

This is kind of "dangerous" because it could mess up replicas if you use them, and idempotency if reloading is needed, etc.  But, I think it might be possible now.  I'm not sure whether this is "Imply only", I don't think so.

1. Prerequisites
Ensure the `imply-utility-belt` extension is enabled in the Imply Manager if you are using Imply manager. If the extension is missing, you will receive an error stating: _“function 'system_time_millis' is not defined”_.

2. Implementation Add this to your `transformSpec`:
```"transforms": [
{
"type": "expression",
"name": "systime",
"expression": "system_time_millis()"
}
]```
Then define the dimension as the following

```{
"type": "long",
"name": "systime",
"multiValueHandling": "SORTED_ARRAY",
"createBitmapIndex": false
},```
