Have InProcessNetworkStack override NetworkStack

This avoids shipping both APKs on Go devices, as would be previously
done with the default Go configuration that still included NetworkStack.

Test: Flashed, booted walleye with svelte config. Verified that
      NetworkStack is not on the device and InProcessNetworkStack is
      used. WiFi working.
Bug: 132666298
Change-Id: If4a7a003128a555e512c88469653c3fb2ad864d5