Add configurable escrow file import GCS bucket

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=123760355

java/google/registry/config/TestRegistryConfig.java

@@ -67,6 +67,11 @@ public class TestRegistryConfig implements RegistryConfig {
     return getProjectId() + "-zonefiles";
   }
 
+  @Override
+  public String getEscrowFileImportBucket() {
+    return getProjectId() + "-escrow-import";
+  }
+
   @Override
   public boolean getTmchCaTestingMode() {
     return true;