Standardize error messages from invalid shapes for Mkl MatMul and Bat…
Hi @penpornk,
For the test failure that https://github.com/tensorflow/tensorflow/pull/60355 introduced, the expected error return that's being tested is unchanged, and the error returned on x86, from `mkl_matmul_op.cc`, is unchanged. So the x86 test should be OK.
The changes this makes to the error reported by `mkl_batch_matmul_op.cc` (making it consistent with the same error from `mkl_matmul_op.cc`) don't appear to feature in any other tests. So I don't think there are any tests on x86 expecting the old error message from `mkl_batch_matmul_op.cc`.
So I think there's no need to guard the change.
 That's great, thanks @penpornk. 
This PR:
- fixes the failing test on Arm CI caused by #60355
- standardizes the use of In[0], In[1] instead of lhs, rhs in error messages