[realms] Define Logdog permissions.
[realms] Define Logdog permissions.

R=40f3d43a28ebae3cb819288542e1c84d73d962d5@chromium.org, tandrii@chromium.org
BUG=1172492

Change-Id: Id4cf4c77662829d497daa8a3d34424e7ba88df72
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-py/+/2660277
Reviewed-by: Robbie Iannucci <40f3d43a28ebae3cb819288542e1c84d73d962d5@chromium.org>
Commit-Queue: Vadim Shtayura <9f116ddb1b24f6fc1916a676eb17161b6c07dfc1@chromium.org>

luci/luci-py,luci/luci-py,luci/luci-py,luci/luci-py