Make sorting locale-aware on Android

[pkerling]

Roadmap or todo suggestion

Detailed Description

Android libc does not support locales, which we need for locale-aware sorting (e.g. sorting "Ä" after "A" and not at the end of the list in German). So we need another, proper solution. Options would be to use the JNI to call the locale-aware Java functions or use libICU, which has locale-aware comparison abilities. The latter option seems most promising. There is a wrapper library available unofficially (android-ndk/ndk#548) that allows to use the C API of the system-bundled libICU, so we would not even have to build and ship it (data files are quite large). We would have to integrate the wrapper and headers though.

Context

Required to get list sorting on Android on-par with all other platforms

Possible Implementation

See #12268 (comment) - that should basically be all

Additional context, screenshots or links

Here are some relevant links or screenshots

Prior attempt in v18: #12268

Issues that appeared: #14952, #15026

Note: Team Kodi will consider this item however we will not make any promises if it will be included.