Finish YAMLification of last necessary config values

There are still some options in RegistryConfig that can't be configured
in YAML, but it's not clear why anyone would need to change them from
their default values.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=146482435

javatests/google/registry/flows/session/HelloFlowTest.java

@@ -31,7 +31,7 @@ public class HelloFlowTest extends FlowTestCase<HelloFlow> {
     runFlowAssertResponse(
         loadFileWithSubstitutions(
             getClass(),
-            "greeting_crr.xml",
+            "greeting.xml",
             ImmutableMap.of("DATE", clock.nowUtc().toString(dateTimeNoMillis()))));
   }
 }