[Reporting] Add telemetry for deprecated export type usage

[tsullivan]

Following adding support of 6.2 PDF job POST URLs in 8.0, #108271, there needs to be telemetry data collected on the extent of usage of deprecated export types.

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[stacey-gammon]

Do we have telemetry that lets us know how often these legacy-style URLs are being used?

[tsullivan]

@stacey-gammon

Do we have telemetry that lets us know how often these legacy-style URLs are being used?

Not at the moment. The telemetry metrics tell us how often each type of export is used, butprintable_pdf export type has this compatibility override making it support both the old-style job params and new-style.

I added this issue to add metadata in the compatibility layer and add it to telemetry, so we can count how often the old-style job params are still being used: #108118

[tsullivan]

@stacey-gammon I've updated the issue title and description

[stacey-gammon]

Thanks @tsullivan! I think that means we can remove the breaking change label now?

[tsullivan]

Closed via #108118