charts/promscale: update alerts

[paulfantom]

What this PR does / why we need it

Syncing alerts from promscale

Which issue this PR fixes

(optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged)

• fixes #

Special notes for your reviewer

Checklist

• [x] Chart Version bumped
• [x] CLA signed

[nhudson]

Sorry looks like I did the same thing in #500