Use an in-process APK for in-process NetworkStack

Instead of having a library in the classpath where the NetworkStack is
created by reflection on devices using the network stack in-process,
just bind to a version of the network stack service that runs in the
system process.

If the in-process version is installed it will be used, otherwise the
module is used with its own process.

Bug: 127908503
Test: blueline boots and has functional WiFi
Test: atest FrameworksNetTests NetworkStackTests
Test: svelte build boots and has functional WiFi
Change-Id: I7722b173e5686e0dbb9cfddcfb34344b0f4135d9