Share gateway IP address between OpenWRT instances am: 2fb899a07f am: 171611e0bd

Original change: https://android-review.googlesource.com/c/platform/external/openwrt-prebuilts/+/2390994

Change-Id: I5794a13f62769809ced051bd804879dc0be5ab97
Signed-off-by: Automerger Merge Worker <[email protected]>