Discover interval silently ignores too small intervals

[LeeDr]

Kibana version: 5.1.1 (same on Kibana 4.6.3)

Elasticsearch version: 5.1.1

Server OS version: Windows, Ubuntu

Browser version: Chrome, Firefox

Browser OS version:

Original install method (e.g. download page, yum, from source, etc.):

Description of the problem including expected versus actual behavior:
On Discover tab with a time-based index selected, if you select a histogram interval too small (it would create too many buckets) Kibana adjusts the interval to produce 500 or less buckets, but it leaves your selection in the interval selection box and still updates the X-Axis label to show your invalid interval.

For example, select "Second" when your time picker time span is multiple days. But also the same for larger intervals which would create too many buckets.

Steps to reproduce:

1. Go to Discover and select any time-based index pattern which has data
2. select a time span where you have data, and then use the Absolute time span settings to select a span of 8 minutes 20 seconds. For example, 2016-12-02 10:19:00.000 to 2016-12-02 10:27:20.000
3. In the histogram select second. The chart should show 500 thin lines for 8 minutes and 20 seconds (500 seconds)
4. Change your time span to add 1 second more
5. the chart refreshes to show fewer bars but still shows second in the interval selection and in the x-axis label.
   I've seen some cases where the histogram is showing bars per 5 seconds but the legend and the selection still says second (there's 12 bars per minute);
   

If you use the browser Refresh, now it shows the actual by 5 seconds in the interval (but the x-axis legend still says @timestamp per second);

With the same timespan, select histogram interval millisecond. That value stays in the interval selection, and the histogram legend is @timestamp per millisecond but the chart is still actually showing by 5 seconds. Refreshing the page again shows the discrepancy;

So somewhere in the process, we decide the interval is too small and would return more than 500 buckets of aggregated data and we increase the size of the time interval, but we DON'T update the interval selection list or x-axis label with that information.

Comparing Kibana 4.6.3, this doesn't not appear to be a regression from that version.

Errors in browser console (if relevant):
none

Provide logs and/or server output (if relevant):
none

[lukasolson]

Duplicate of #6295.