How to define the time column in the inline datasource?

The only example I found for inline datasource is in the querying datasource page, but it does not contain a time column https://druid.apache.org/docs/latest/querying/datasource.html#inline.

I tried to use `__time` name with a timestamp, millisecond precision timestamp, or ISO8601 but without luck, at least for no `timeBoundary` query.

```json
{
"dataSource": {
"columnNames": [
"__time",
"val"
],
"rows": [
[
1556668800000,
123
],
[
1559347200000,
456
],
[
1561939200000,
789
]
],
"type": "inline"
},
"queryType": "timeBoundary"
}
```
Actual results
|maxTime |minTime |
|----------------------|------------|
|146140482-04-24T15:36:27.902Z|-146136543-09-08T08:23:32.096Z|

Expected results
|maxTime |minTime |
|----------------------|------------|
|2019-07-01T00:00:00.000Z|2019-05-01T00:00:00.000Z|

Start with the Inline datasource section of the Druid querying datasource documentation and reproduce the supplied timeBoundary query using the JSON rows shown. Check how the __time column is interpreted for inline data and document the valid representation and expected minTime/maxTime behavior. Done means the page explains the time column clearly and the example produces the intended dates.

Written by the indexing model from the issue text.