Auto merge of #14528 - mmatyas:android_cppruntime, r=larsbergstrom

Add C++ runtime shared object to the Android APK

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At the moment, the Android port requires `libc++_shared.so` to run -- this patch adds the file to the generated APK.

Part of #13154.

If you know a cleaner way to solve this issue, feel free to share it! Static linking didn't work, see the related issue.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

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