Android release

Not much of the functionality has changed, but I am making an initial Android release. The code to the android base can be found at https://github.com/oxagast/ansvif_android. This is just the APK, as the source code is hosted in the other separate GitHub repository.
Note that the binary for arm64 x86 and x86_64 Androids have not been tested at all, I don't have a device. Feel free to try them though, they're compiled!