[automerger skipped] Fix docs: clarify usage of float16 scalars in operations am: 0a9895d9
am: 055f5d6a -s ours
am skip reason: change_id I9028c4a109c80f0b8571fab45555818e9e4bc783 with SHA1 6d13ba25 is in history
Change-Id: Ie117ce367ae3bb06fb8b233dd22e73fc99b48169