Share gateway IP address between OpenWRT instances am: 2fb899a07f am: 171611e0bd am: affabf9324

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

Change-Id: I10202391ebbad58baa5aa00c00c82a9e8c0257eb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>