Revert "Stop parsing command line arguments every time common_utils is imported. (#156703)"

This reverts commit ac7b4e7fe4d233dcd7f6343d42b4fa3d64bce548.

Reverted https://github.com/pytorch/pytorch/pull/156703 on behalf of https://github.com/clee2000 due to failing internally D80206253, see above comment for details ([comment](https://github.com/pytorch/pytorch/pull/156703#issuecomment-3362156908))

torch/testing/_internal/common_distributed.py

@@ -33,7 +33,6 @@ import torch.nn as nn
 from torch._C._autograd import DeviceType
 from torch._C._distributed_c10d import _SymmetricMemory
 from torch._logging._internal import trace_log
-from torch.testing._internal import common_utils
 from torch.testing._internal.common_utils import (
     FILE_SCHEMA,
     find_free_port,
@@ -773,12 +772,7 @@ class MultiProcessTestCase(TestCase):
             process = proc(
                 target=self.__class__._run,
                 name="process " + str(rank),
-                args=(
-                    rank,
-                    self._current_test_name(),
-                    self.file_name,
-                    child_conn,
-                ),
+                args=(rank, self._current_test_name(), self.file_name, child_conn),
                 kwargs={
                     "fake_pg": getattr(self, "fake_pg", False),
                 },
@@ -855,7 +849,6 @@ class MultiProcessTestCase(TestCase):
             torch._C._set_print_stack_traces_on_fatal_signal(True)
         # Show full C++ stacktraces when a Python error originating from C++ is raised.
         os.environ["TORCH_SHOW_CPP_STACKTRACES"] = "1"
-        common_utils.set_rng_seed()
 
         # self.id() == e.g. '__main__.TestDistributed.test_get_rank'
         # We're retrieving a corresponding test and executing it.
@@ -1677,10 +1670,6 @@ class MultiProcContinuousTest(TestCase):
         self.rank = cls.rank
         self.world_size = cls.world_size
         test_fn = getattr(self, test_name)
-
-        # Ensure all the ranks use the same seed.
-        common_utils.set_rng_seed()
-
         # Run the test function
         test_fn(**kwargs)