[resultui] support changing configs without restarting the dev server
[resultui] support changing configs without restarting the dev server

R=jsca@google.com, 7f5d2f4f6ce87649784e35ad551490ab8d89e8eb@google.com

Change-Id: I4f94c4ef3dacd166b3e20e3477e51db850b1a307
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2560449
Auto-Submit: Weiwei Lin <968518a24f41fef00b747498600e52b792d06ae0@google.com>
Reviewed-by: Quang Minh Tuan Nguyen <7f5d2f4f6ce87649784e35ad551490ab8d89e8eb@google.com>
Commit-Queue: Quang Minh Tuan Nguyen <7f5d2f4f6ce87649784e35ad551490ab8d89e8eb@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go