Add action to sync all Registrar RDAP base URLs from the ICANN endpoint

We aren't turning on the cron job yet - we want to make sure it works correctly first.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=252726789

java/google/registry/module/backend/BUILD

@@ -30,6 +30,7 @@ java_library(
         "//java/google/registry/model",
         "//java/google/registry/module",
         "//java/google/registry/monitoring/whitebox",
+        "//java/google/registry/rdap",
         "//java/google/registry/rde",
         "//java/google/registry/reporting",
         "//java/google/registry/reporting/billing",