Xamarin.iOS and Xamarin.Android bindings

[bemartin]

This PR includes:

• Android and iOS Xamarin bindings for methods available in both Java and Obj-C wrappers
• Test projects to validate the bindings
• build-xamarin.sh script to build C++ SDK, Obj-C/Java wrappers and Xamarin bindings
• Initial Xamarin.md documentation on building and consuming the Xamarin bindings

[Max Golovanov (maxgolov)]

I like all of it. Could you please double-check that the test failures are not related to your commit?

[Max Golovanov (maxgolov)]

When you integrate it - I'd like to compile it, get the assembly, then diff versus what we generate using C++/CX on Windows. If there are some significant differences, we can address these in a separate PR. BTW, old nuget packaging scripts are located here:
https://github.com/microsoft/cpp_client_telemetry/blob/master/tools/build-nugets.cmd
https://github.com/microsoft/cpp_client_telemetry/tree/master/tools/NuGet/uap

We are not using these scripts for a while now. But it might be something that we can restart doing, including both Xamarin for other OS + Windows 10 C++/CX projection in one nuget. I think if we use GitHub Actions cache or some external storage account, we might be able to aggregate different platform SDK bits into one C# nuget.

[bemartin]

I like all of it. Could you please double-check that the test failures are not related to your commit?

I re-executed the tests and they are all green now. It seems to have been some transient issue. I did not see any issues when running the tests locally either

[Max Golovanov (maxgolov)]

bemartin - could you convert this to "Ready for Review"? I think it should be safe to add your change to the master.

[bemartin]

When you integrate it - I'd like to compile it, get the assembly, then diff versus what we generate using C++/CX on Windows. If there are some significant differences, we can address these in a separate PR. BTW, old nuget packaging scripts are located here:
https://github.com/microsoft/cpp_client_telemetry/blob/master/tools/build-nugets.cmd
https://github.com/microsoft/cpp_client_telemetry/tree/master/tools/NuGet/uap

We are not using these scripts for a while now. But it might be something that we can restart doing, including both Xamarin for other OS + Windows 10 C++/CX projection in one nuget. I think if we use GitHub Actions cache or some external storage account, we might be able to aggregate different platform SDK bits into one C# nuget.

I will look into the nugets scripts a little bit later and see if I can revive this as a follow up PR. Is that ok?
I have a couple of additional changes to make but I am hoping to publish the PR today or tomorrow

[bemartin]

bemartin - could you convert this to "Ready for Review"? I think it should be safe to add your change to the master.

I have to fix a couple of small things that I found while testing locally but I will publish it ASAP

[Max Golovanov (maxgolov)]

Is there a way we can call this script from build.sh, so that we have one single entry point? That may not be a hard requirement, but would be nice. I am thinking of this like, once we integrate the vcpkg install mstelemetry - we can also create a triplet that compiles with Xamarin / C# projeciton from there.

[bemartin]

we could but this script builds the C++ code, Obj-c and Java wrappers and then the Xamarin bindings. This will be adding about 20 minutes of build time and will require anybody using this script to have VS with Xamarin installed.
This script also requires running build on Mac since it's building Obj-c code.

Are we ok with those requirements/constraints?

[Max Golovanov (maxgolov)]

I'm not suggesting to do it every time, but maybe an option in the build.sh to trigger build-xamarin.sh as well. Maybe not in this PR, but after the merge of mine: #644 - then we can control in vcpkg install mstelemetry:x64-macos-csharp , for example, to build both - core and Xamarin.

[Max Golovanov (maxgolov)]

I would suggest we merge it-as is. All checks passed.