[database watcher] Pad time interval to include a successful probe

[dimitri-furman]

Summary

Problem

When all connectivity probes in a time range have failed, no data is displayed on the Connectivity dashboards. This happens because the SQL target identifiers such as logical server name and database name are not available in the failed probe data.

Solution

Expand (pad) the time range to increase the probability of finding a successful probe with the required SQL target identifiers.

Validation

• Validate your changes using one or more of the testing methods.

Checklist

• If you are adding a new template, gallery, or folder, add your team and folder/file(s) to the CODEOWNERS file at the root of the repo. CODEOWNERS entries should be teams, not individuals.
  When done correctly, this means that from then on your team does reviews of your things, not the workbooks team.
• Ensure all steps in your template have meaningful names.
• Ensure all parameters and grid columns have display names set so they can be localized.