Remove an obsolete TODO(b/196206770)

This TODO comment should also have been removed in my previous CL [1],
which actually addressed the TODO.

There must be no behavior change in this CL.

 [1]: Iba30c7706a991ec5a0a8b94bb62e47a25e6cb4e0
      bcc73036

Bug: 196206770
Bug: 343601565
Test: presubmit
Flag: EXEMPT refactor
Change-Id: If6f081a891ed66e4586b45bbea7441f04d3d3b8e