Change the supervised user icon used throughout Chrome OS to the new family experience kite icon.
Rename some files to supervised_user suffix.

Bug: 1058516
Change-Id: Ief22e51de73b0675c0a9a18969dac8627d9ad30d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2146080Reviewed-by: Aga Wronska <agawronska@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Evan Stade <estade@chromium.org>
Commit-Queue: Xiqi Ruan <xiqiruan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760180}