The IPv6 addresses in ring_*_device resource names should be surrounded
by []. This ensures the address is properly formatted when the resource
is define in swift::storage::node.
Closes-Bug: #1997295
Change-Id: I390f3c7bbfbbbc7217f81e8a0312e5db201ef409
(cherry picked from commit a8ef5f69060adda86433ff2de4c761a0f86f68c3)