Add tracking for cluster application installs

app/services/clusters/applications/check_installation_progress_service.rb

@@ -11,6 +11,8 @@ module Clusters
 
       def on_success
         app.make_installed!
+
+        Gitlab::Tracking.event('cluster:applications', "cluster_application_#{app.name}_installed")
       ensure
         remove_installation_pod
       end

spec/services/clusters/applications/check_installation_progress_service_spec.rb

@@ -160,6 +160,12 @@ describe Clusters::Applications::CheckInstallationProgressService, '#execute' do
         expect(application).to be_installed
         expect(application.status_reason).to be_nil
       end
+
+      it 'tracks application install' do
+        expect(Gitlab::Tracking).to receive(:event).with('cluster:applications', "cluster_application_helm_installed")
+
+        service.execute
+      end
     end
 
     context 'when installation POD failed' do