Fix spec data categories to lowercase

ee/spec/services/ee/service_ping/build_payload_service_spec.rb

@@ -9,7 +9,7 @@ RSpec.describe ServicePing::BuildPayloadService do
     include_context 'stubbed service ping metrics definitions' do
       let(:subscription_metrics) do
         [
-          metric_attributes('license_md5', "Subscription")
+          metric_attributes('license_md5', "subscription")
         ]
       end
     end

spec/support/shared_contexts/services/service_ping/stubbed_service_ping_metrics_definitions_shared_context.rb

@@ -6,7 +6,7 @@ RSpec.shared_context 'stubbed service ping metrics definitions' do
   let(:metrics_definitions) { standard_metrics + subscription_metrics + operational_metrics + optional_metrics }
   let(:standard_metrics) do
     [
-      metric_attributes('uuid', "Standard")
+      metric_attributes('uuid', "standard")
     ]
   end