Add billing pipeline to cron

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=181793243

java/google/registry/env/production/default/WEB-INF/cron.xml

@@ -255,10 +255,28 @@
     <url><![CDATA[/_dr/cron/fanout?queue=retryable-cron-tasks&endpoint=/_dr/task/icannReportingStaging&runInEmpty]]></url>
     <description>
       Create ICANN activity and transaction reports for last month, storing them in
-      gs://domain-registry-alpha-reporting/icann/monthly/yyyy-MM
+      gs://[PROJECT-ID]-reporting/icann/monthly/yyyy-MM
       Upon success, enqueues the icannReportingUpload task to POST these files to ICANN.
     </description>
     <schedule>2 of month 09:00</schedule>
     <target>backend</target>
   </cron>
+
+  <cron>
+    <url><![CDATA[/_dr/cron/fanout?queue=retryable-cron-tasks&endpoint=/_dr/task/generateInvoices&runInEmpty]]></url>
+    <description>
+      Starts the beam/InvoicingPipeline Dataflow template, which creates the overall invoice and
+      detail report CSVs for last month, storing them in gs://[PROJECT-ID]-billing/invoices/yyyy-MM.
+      Upon success, sends an e-mail copy of the invoice to billing personnel, and copies detail
+      reports to the associated registrars' drive folders.
+      See GenerateInvoicesAction for more details.
+    </description>
+    <!--WARNING: This must occur AFTER expandRecurringBillingEvents and AFTER exportSnapshot, as
+    it uses Bigquery as the source of truth for billable events. ExportSnapshot usually takes
+    about 2 hours to complete, so we give 11 hours to be safe. Normally, we give 24+ hours (see
+    icannReportingStaging), but the invoicing team prefers receiving the e-mail on the first of
+    each month. -->
+    <schedule>1 of month 17:00</schedule>
+    <target>backend</target>
+  </cron>
 </cronentries>