[automerger skipped] Adds float16 support for RANDOM_MULTINOMIAL. am: 41e6732a66 am: d28d569c0e
am: ce84523028 -s ours
am skip reason: change_id Iac8c0c23a8219702697a7a126e5e2e43ef0461f4 with SHA1 5b2615be21 is in history

Change-Id: I51607359e4ab03747915bda41a676d724c81d01e