Ensure that StandardContext comes first in the list of contexts

lib/gitlab/tracking.rb

@@ -25,10 +25,10 @@ module Gitlab
       end
 
       def event(category, action, label: nil, property: nil, value: nil, context: [], project: nil, user: nil, namespace: nil) # rubocop:disable Metrics/ParameterLists
-        context += [Tracking::StandardContext.new(project: project, user: user, namespace: namespace).to_context]
+        contexts = [Tracking::StandardContext.new(project: project, user: user, namespace: namespace).to_context, *context]
 
-        snowplow.event(category, action, label: label, property: property, value: value, context: context)
-        product_analytics.event(category, action, label: label, property: property, value: value, context: context)
+        snowplow.event(category, action, label: label, property: property, value: value, context: contexts)
+        product_analytics.event(category, action, label: label, property: property, value: value, context: contexts)
       end
 
       def self_describing_event(schema_url, data:, context: nil)

spec/lib/gitlab/tracking_spec.rb

@@ -61,8 +61,8 @@ RSpec.describe Gitlab::Tracking do
           expect(args[:property]).to eq('property')
           expect(args[:value]).to eq(1.5)
           expect(args[:context].length).to eq(2)
-          expect(args[:context].first).to eq(other_context)
-          expect(args[:context].last.to_json[:schema]).to eq(Gitlab::Tracking::StandardContext::GITLAB_STANDARD_SCHEMA_URL)
+          expect(args[:context].first.to_json[:schema]).to eq(Gitlab::Tracking::StandardContext::GITLAB_STANDARD_SCHEMA_URL)
+          expect(args[:context].last).to eq(other_context)
         end
 
         described_class.event('category', 'action', label: 'label', property: 'property', value: 1.5,