Revert D26820202: Support mix of int32 and int64 offsets/indices for EmbeddingBag and its variants
Test Plan: revert-hammer
Differential Revision:
D26820202 (https://github.com/pytorch/pytorch/commit/f9097c43b95e4fe94ec55071bcb22968bdc40e83)
Original commit changeset: 3e8f09523329
fbshipit-source-id: 5742b69a96ce1c848d75348d0f761cf66a69cbf3
