[TestZeroRedundancyOptimizer] Add multi gpu checker (pytorch#53564)

Summary:
The test test_collect_shards fails on single GPU setup.
Enabling the multi gpu checker.

Signed-off-by: Jagadish Krishnamoorthy <[email protected]>

Pull Request resolved: pytorch#53564

Reviewed By: H-Huang

Differential Revision: D26952325

Pulled By: rohan-varma

fbshipit-source-id: e8956f9277c7320024bece129767e83fbdf02b2c

Author: jaglinux

test/distributed/optim/test_zero_redundancy_optimizer.py

@@ -346,6 +346,7 @@ def some_trainable():
         all_trainable()
         some_trainable()
 
+    @common_distributed.skip_if_not_multigpu
     def test_collect_shards(self):
         """ Check the state consolidation mechanism, and the state dict exposed by ZeroRedundancyOptimizer"""
         self.dist_init(self.rank)