Allow objc.signing_certificate_name to return None in Skylark.
MOS_MIGRATED_REVID=147375812
@@ -292,7 +292,7 @@ public class ObjcConfiguration extends BuildConfiguration.Fragment {
* certificate was specified.
*/
@Nullable
- @SkylarkCallable(name = "signing_certificate_name", structField = true,
+ @SkylarkCallable(name = "signing_certificate_name", structField = true, allowReturnNones = true,
doc = "Returns the flag-supplied certificate name to be used in signing, or None if no such "
+ "certificate was specified.")
public String getSigningCertName() {
