Translating strings in the zh-rCN and zh-rTW values folders

To whom it may concern:

My name is Kyle, and I am working on an assignment for my new job as an Android developer. The assignment  requires me to submit a pull request to an open-source project. I know this is only a small change (a few strings in the Mandarin-language files), but hopefully this will improve the experience of Mandarin-speaking Anki-Android users across the globe! 

Enjoy your day,
Kyle O.