* Alerting: Remove double quotes from matchers
With #38629 a new Alertmanager configuration object was introduced with `object_matchers`, it was meant to circumvent around the fact that Prometheus label names don't support a set of characters that Grafana needs to support for alerts, silences, matchers, etc. (with a common example being elasticsearch's `.`).
This new object does not include the label of sanitzation or validation that its Prometheus equivalent supports in `matchers` and therefore are semantically not equivalent.
This triggered the problem that when the migration is run, we use `matchers` as the object to populate in configuration for routing policies, but when the UI does its first save this object is transformed to `object_matchers`.
Matchers that were previously running just fine would immediately stop working as soon as the configuration is saved.
This problem surfaced with the introduction of #49952 where we stopped stripping double quotes from matchers (not just regex but _all_ of them).
* Add comment explaining rationale and future removal
Co-authored-by: Alex Weaver <weaver.alex.d@gmail.com>
(cherry picked from commit 1a50b0dbb7)
Co-authored-by: gotjosh <josue.abreu@gmail.com>
Alexander Weaver
8efd4350b4