Kibana version: 7.8.0-BC2

Elasticsearch version:7.8.0-BC2

Original install method: cloud

Description of the problem including expected versus actual behavior:

When setting a non-default interval size in the alert condition expression, it only applies to the first condition. All subsequent conditions use the default interval of one minute:

Steps to reproduce:

1. Navigate to the metrics UI.
2. Create an alert with multiple conditions and a custom aggregation interval that is significantly larger or smaller than the default.
3. Separately cause the first and then any condition after the first to trigger.
4. Observe that the alert triggers on differently time scales for the first compared to the second.

Expected behavior:
The configured aggregation interval applies to all conditions equally.