feat(android): Add Android builds to CI

[rwalworth]

Description:
This PR adds Android builds of the C++ SDK to the Github workflows. It will only generate the builds after a PR is merged as to not slow down development. A couple notes:

• vcpkg needed to upgraded as the baseline we were using was too old for Android builds.
• Switched to using spdlog logging library in place of log4cxx simply because vcpkg currently supports spdlog but not log4cxx android builds.
• The Android build is currently done in a docker container, but it could be possibly be done straight on our Github runners as they are linux-x86_64 if this wanted to be looked into later. I tried this but there was an issue finding git that I couldn't figure out quickly.
• There is an issue testing the Android test executables on an emulator running in an x86_64 environment; even running an arm64 docker container in an x86_64 host environment there were issues. If we would like to test these Android builds in CI, this will need to be figured out. However, I left instructions in the Dockerfile as to how to run the test executables.
• Some work was done that involved building the examples into Android APKs. This was eventually abandoned, but I left some of the work I had done for that in the Dockerfile as well in case this wants to be done in the future.
• The examples executables were being installed twice unnecessarily so I removed this.
• We are now installing gtest via vcpkg instead of manually through CMake.
• Some filepaths needed updating.
• Many files had unnecessary includes that I removed.

Related issue(s):

Fixes #660

Checklist

• Documented (Code comments, README, etc.)
• Tested (unit, integration, etc.)

[gsstoykov]

Overall LGTM but shouldn't we wait and see how the communication with the community member goes before pushing this into main? As I saw we still don't have answers from the community member and we would only introduce more configurations and docker pipeline overhead.

[rwalworth]

Overall LGTM but shouldn't we wait and see how the communication with the community member goes before pushing this into main? As I saw we still don't have answers from the community member and we would only introduce more configurations and docker pipeline overhead.

I could go either way. I have the Android builds only being generated on merge so it won't impact development time. Maybe @SimiHunjan can weigh in here.

[gsstoykov]

LGTM.

[rwalworth]

Not merging for the time being, leaving work on protected branch however