Does not self allocate IDs in Beam by default. (#1809)

* Does not self allocate IDs in Beam by default.

Per b/250948425, it is dangerous to implicitly allow all Beam pipelines
to create buildables by self allocating the IDs. This change makes it so
that one has to explicitly request self allocation in Beam.

A boolean is added to the pipeline option so that it can be passed to
the beam worker initializer that controls the behavior of the JVM on
each worker. Note that we did not add the option in the metadata.json file
because we did not want people to use the override at run time when launching
a pipeline, due to the risk. As shown in RdePipeline.java, we instead
explicitly hard-code the option in the pipeline. There is nothing that
stops one to supply that option when launching the pipeline, but it's
not advised.

Tested=deployed the pipeline alpha and ran it.

core/src/test/java/google/registry/testing/AppEngineExtension.java

@@ -40,7 +40,7 @@ import com.google.common.collect.Sets;
 import com.google.common.io.Files;
 import com.googlecode.objectify.Key;
 import com.googlecode.objectify.ObjectifyFilter;
-import google.registry.model.IdService;
+import google.registry.model.IdService.SelfAllocatedIdSupplier;
 import google.registry.model.ofy.ObjectifyService;
 import google.registry.model.registrar.Registrar;
 import google.registry.model.registrar.Registrar.State;
@@ -441,7 +441,7 @@ public final class AppEngineExtension implements BeforeEachCallback, AfterEachCa
 
     ObjectifyService.initOfy();
     // Reset id allocation in ObjectifyService so that ids are deterministic in tests.
-    IdService.resetSelfAllocatedId();
+    SelfAllocatedIdSupplier.getInstance().reset();
     this.ofyTestEntities.forEach(AppEngineExtension::register);
   }