Visual Builder interval auto for Top N, Metric and Gauge

[tommikiviniemi-srs]

Kibana version:

6.4.1

Elasticsearch version:

6.4.1

Any additional context:

This may or may not be a bug in the Visual Builder. Let's say the visualised time range is last 7 days and the visualisation's interval is set to anything than "7d", Top N, Metric and Gauge will show only the last "tick"'s value from the Time Series. So if the timespan is set to auto Gauges will show 0% most of the time. I would have assumed that considering they are not timing based per se they'd show an average for the entire time. I can of course force the panel's interval to 7d, but then picking any visualisation range shorter than 7d will not work.

In other words shouldn't interval "auto" for Top N, Metric and Gauge be equivalent to selecting an interval that coincides with the selected time span? I don't think the current behaviour for auto is really useful or expected.

[rayafratkina]

Related to #15760