Make OpenWRT IP address changable dynamically based on base_instance_num am: 6df3b6e14d am: 8366435d89 am: 104ceaaec8

Original change: https://android-review.googlesource.com/c/platform/external/openwrt-prebuilts/+/2369050

Change-Id: I50f189b9515e82d1ea09e68f393aa002d346f662
Signed-off-by: Automerger Merge Worker <[email protected]>