RMX1921: rro_overlays: overlay tethering and wifi stack from Google

Evolution X ships com.google.android.tethering.apex and com.google.android.wifi as prebuilt apex by
default. Therefore, adapt the overlay to properly enable platform
specific tethering and WiFi configs.

Signed-off-by: Chenyang Zhong <zhongcy95@gmail.com>
Signed-off-by: Joey Huab <joey@evolution-x.org>
Signed-off-by: kaderbava <ksbava7325@gmail.com>