Merge "Add the constant for IPv6 all-routers/nodes/hosts multicast address." am: 46baaac36b am: 71584aba6e

Original change: https://android-review.googlesource.com/c/platform/frameworks/libs/net/+/1562252

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I0cc204998a1c7f3c324ea962902b7107a5b805b9