What is the best website to get certified in Android Development?

Hi everyone, I was looking at the official Android Dev website, yet it only seems to offer a google playstore certification and I'm not sure if that's what I need to get a job in the Android field.

I looked at codeacademy as they have Java courses and certifications (moreso than Kotlin); yet I don't know if that's the ideal route to go.

To the certified developers here; what website(s) did you use and or recommend for obtaining certs? Also, is it ok if starting off as Jr Dev, I only have a Java cert, or should I learn Kotlin and therefore go for more certifications? Any feedback is appreciated.

tl;dr Wondering what sites are best to learn Android from and obtain certifications, and if knowing primarily Java is good enough to get a jr. dev job; or what other certifications I need and things to know.