Apply the sharding on RngBitGeneratorOp itself, instead of its tuple elements.
Apply the sharding on RngBitGeneratorOp itself, instead of its tuple elements.

When exporting RngBitGeneratorOp, whose output shape is tuple of (output_state, output), we apply the sharding on the op itself. We also create GetTupleElement, which should not share the same sharding with RngBitGeneratorOp.

Add a test case that fails before this cl and succeeds with this cl.
