Merge new metrics implemented with Instrumentation classes to Usage Ping [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

Proposal to use instrumentation classes

Merge Instrumented metrics to usage ping

  - Add feature flag usage_data_instrumentation
  - Merge metrics generated using instrumentation
  classes to usage ping generated using
  usage_data.rb

Using a feature flag to first have the chance that this works correct and doesn't break the usage ping in the current state.

A couple of metrics values are overriten by values generated using Gitlab::UsageDataMetrics.uncached_data

When we remove the feature flag we could remove the implementation from usage_data.rb and only use the one from instrumentation classes.

Metrics overitten now are

{
  :usage_activity_by_stage=>
  {
    :plan=>{:issues=>172944}
  }, 
  :counts=>
  {
    :boards=>261010, 
    :issues=>6343079
  }, 
  :redis_hll_counters=>
  {
  :quickactions=>
  {
    :i_quickactions_approve_weekly=>0, 
    :i_quickactions_approve_monthly=>0
  }
  }, 
  :uuid=>"ea8bf810-1d6f-4a6a-b4fd-93e8cbd8b7f", 
  :hostname=>"staging.gitlab.com", 
  :usage_activity_by_stage_monthly=>
  {
    :plan=>
    {
    :issues=>12
    }
  }
}

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

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• Label as security and @ mention @gitlab-com/gl-security/appsec
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Related to #326426 (closed)