If the DVR+HA router has external gateway, the snat-namespace will be
initialized twice during agent restart. And that ns initialization
function will run many external resource processing actions which will
definitely increase the starting time of L3 agent. This patch addresses
this issue.
Change-Id: I7719491275fa1ebfa7e881366e5cb066e3d4185c
Closes-Bug: #1850779
(cherry picked from commit 7a9d6d2641)