I put this PR as a draft to validate the implementation. Please let me know if I am moving in the right track.
Also, I did the testing with several apps, including the Unity app with two-instance creation. For all tests, the gRPC service runs successfully.

you'll also need to update the Vulkan side as well, otherwise the server will be started twice for Vulkan application.
please also test with Vulkan application, OpenXR application, and also the shared Unity application that we know has problem.

you'll also need to update the Vulkan side as well, otherwise the server will be started twice for Vulkan application. please also test with Vulkan application, OpenXR application, and also the shared Unity application that we know has problem.

I added also a global object to initialize the server for an Vulkan app, however, it is not working. It seems the server is closed. When I move the server initialization to DiveInterceptCreateInstance at vk_layer_base.cc it works.

initialize

Did you find out why? In theory it should, as it's just move the place of initialization.

I have updated this PR which now works for all tests I have.
The problem was that the loading/unloading behavior of the Vulkan/OpenXR Dive layer library varies significantly across Android applications.For example for Vulkan apps it loads - unloads - reloads the library during execution. For an Unity-based OpenXR
app that creates two instances, the behavior is the same.

To addres this now the gRPC Server starts when the library loads for the first time. Then, a function prevents the library from being unloaded. This keeps both the library and server loaded exactly once, even if apps try to reload or close them. In this way, the Server lives for the entire lifecycle of the app.

I updated the PR to support Windows as well.

I tested on Windows, and everything work fine.