Migrate telemetry poller & opt in banner to New Platform

[joshdover]

Now that UI applications can be built in the New Platform. We need to move any features provided by uiExport hacks to the New Platform so that they continue to work when no legacy code is on the page.

These telemetry related hacks need to be migrated:

• plugins/telemetry/hacks/telemetry_init
  • Starts polling for new metrics and sending to backend
• plugins/telemetry/hacks/telemetry_opt_in
  • Shows opt-in banner for telemetry
• plugins/ui_metric/hacks/ui_metric_init
  • Inits some telemetry thing, not clear this should be a hack. Needs more investigation

Related to #42984

[elasticmachine]

Pinging @elastic/kibana-platform

[elasticmachine]

Pinging @elastic/kibana-stack-services

[elasticmachine]

Pinging @elastic/pulse (Team:Pulse)

[joshdover]

@Bamieh friendly reminder, this is one of the last blockers to allowing plugins to migrate their frontend code to the New Platform. Could we get this resolved in 7.7?

[Bamieh]

@joshdover Yes I believe we can have it for ready for 7.7. Can you clarify why this would be blocking migration?

[joshdover]

When NP apps are mounted on the page, we cannot execute any legacy code (including hacks) because they depend on the global Angular instance in the legacy system.

Therefore, these hacks never get executed when a NP app is mounted. We have a handful of plugins that are ready to move over to the NP (which has the UX improvement of reducing the number of times the user has to wait for Kibana frontend to load). We can't move these over until this functionality is ported so that the opt-in banner shows in these apps and telemetry polling runs when these apps are mounted.

[Bamieh]

Got it. Thanks for explaining.