replaced jCenter with mavenCentral

[matteodanelli]

Summary

jCenter will be offline in February 2022. I've updated the android project to use maven.

Test Plan

I've tested the library on a personal project and it builds without issues.

Compatibility

OS	Implemented
iOS	✅
Android	✅.

Checklist

• [X] I have tested this on a device and a simulator
• [X] I added the documentation in README.md
• [X] I updated the typed files (TS and Flow)

[vonovak]

thank you! :)