Enable test_call_method_on_rref in rpc_test (#30261)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/30261
With #29827, the flakiness should disappear for test_call_method_on_rref
Test Plan: Imported from OSS
Differential Revision: D18645036
Pulled By: mrshenli
fbshipit-source-id: 44d759062fc78b1a797266096dbb4ddd104f07eb
