batch size scheduling remove asending batch size constraint (#2686)

Summary:
Pull Request resolved: #2686

In the use case of NE verification for paft, there are cases that global batch will decrease. Remove the sanity check in batch size scheduling to couple with this scenario for NE verification.

Reviewed By: xunnanxu

Differential Revision: D68284699

fbshipit-source-id: 74c975b4599350919d51e21897ce3ee46557c478

Author: Carl Chengyan Fu

torchrec/metrics/metrics_config.py

@@ -236,11 +236,6 @@ def validate_batch_size_stages(
     if len(batch_size_stages) == 0:
         raise ValueError("Batch size stages should not be empty")
 
-    for i in range(len(batch_size_stages) - 1):
-        if batch_size_stages[i].batch_size >= batch_size_stages[i + 1].batch_size:
-            raise ValueError(
-                f"Batch size should be in ascending order. Got {batch_size_stages}"
-            )
     if batch_size_stages[-1].max_iters is not None:
         raise ValueError(
             f"Batch size stages last stage should have max_iters = None, but get {batch_size_stages[-1].max_iters}"