Add CheckGcpProjectBillingWorker

app/workers/check_gcp_project_billing_worker.rb

+class CheckGcpProjectBillingWorker
+  include ApplicationWorker
+
+  def self.redis_shared_state_key_for(token)
+    "gitlab:gcp:#{token}:billing_enabled"
+  end
+
+  def perform(token)
+    return unless token
+
+    billing_enabled = CheckGcpProjectBillingService.new.execute(token)
+    Gitlab::Redis::SharedState.with do |redis|
+      redis.set(self.class.redis_shared_state_key_for(token), billing_enabled)
+    end
+  end
+end

spec/workers/check_gcp_project_billing_worker_spec.rb

+require 'spec_helper'
+
+describe CheckGcpProjectBillingWorker do
+  describe '.perform' do
+    let(:token) { 'bogustoken' }
+    subject { described_class.new.perform(token) }
+
+    it 'calls the service' do
+      expect(CheckGcpProjectBillingService).to receive_message_chain(:new, :execute)
+
+      subject
+    end
+
+    it 'stores billing status in redis' do
+      expect(CheckGcpProjectBillingService).to receive_message_chain(:new, :execute).and_return(true)
+      subject
+
+      Gitlab::Redis::SharedState.with do |redis|
+        expect(redis.get("gitlab:gcp:#{token}:billing_enabled")).to eq('true')
+      end
+    end
+  end
+end