Expand the instrumentation FF coverage

Adding more code under the feature flag which is related to the
Instrumentation intialization and would be removed alongside the code
which is already under the FF.

config/initializers/zz_metrics.rb

@@ -162,6 +162,9 @@ if Gitlab::Metrics.enabled? && !Rails.env.test? && !(Rails.env.development? && d
     config.middleware.use(Gitlab::Metrics::ElasticsearchRackMiddleware)
   end
 
+  # We are removing the Instrumentation module entirely in steps.
+  # More in https://gitlab.com/gitlab-org/gitlab/-/issues/217978.
+  unless ::Feature.enabled?(:method_instrumentation_disable_initialization)
     # This instruments all methods residing in app/models that (appear to) use any
     # of the ActiveRecord methods. This has to take place _after_ initializing as
     # for some unknown reason calling eager_load! earlier breaks Devise.
@@ -178,9 +181,6 @@ if Gitlab::Metrics.enabled? && !Rails.env.test? && !(Rails.env.development? && d
         ActiveRecord::Querying.public_instance_methods(false).map(&:to_s)
       )
 
-    # We are removing the Instrumentation module entirely in steps.
-    # More in https://gitlab.com/gitlab-org/gitlab/-/issues/217978.
-    unless ::Feature.enabled?(:method_instrumentation_disable_initialization)
       Gitlab::Metrics::Instrumentation
         .instrument_class_hierarchy(ActiveRecord::Base) do |klass, method|
           # Instrumenting the ApplicationSetting class can lead to an infinite
@@ -199,9 +199,7 @@ if Gitlab::Metrics.enabled? && !Rails.env.test? && !(Rails.env.development? && d
       # be instrumented.
       Gitlab::Metrics::Instrumentation.instrument_methods(Ability)
     end
-  end
 
-  unless ::Feature.enabled?(:method_instrumentation_disable_initialization)
     Gitlab::Metrics::Instrumentation.configure do |config|
       instrument_classes(config)
     end