Color ranges broken in Metricbeat visualizations

[jshvrsn]

• Version: 6.4.2
• Operating System: Ubunutu 18.04
• Discuss Forum URL: https://discuss.elastic.co/t/color-ranges-broken-in-metricbeat-visualizations/151926
• Steps to Reproduce:

1. Open, for example, "Memory Usage Gauge [Metricbeat System]" visualization in the Kibana visualization editor.
2. Go to the "Panel Options" tab.
3. Look at "Set gauge color to and text color to if metric is" and see that the dropdown is blank, it should say ">= greater than or equal"

There is a typo in the json that builds the visualizations. The "opperator" field should be spelled "operator". Multiple visualizations are affected. I will submit a PR shortly with the fix.