I guess it depends on what you consider "mastering". Android is designed for applications to be written in Java. However, Android uses its own class library rather than extendinding the standard Java classes. (This has Oracle rather upset with Google, since this really does break the "write once, run anywhere" Java model.)

I've played around with Android app development, and it's a bit of a pain. The interpreters are *slow* and the Samsung drivers for testing on my phone are extremely buggy.

I'd suggest learning basics of graphical programming on a desktop with standard Java (after learning the core concepts and classes in a console I/O environment) before moving to Android.

If you hate Java, there is the capability of writing native apps in C, but that's lower-level (you have to do more coding to get anything done) and a compiled app is binary machine code that will only run on one type of phone or tablet. This is rarely done except for writing device-specific utilities and drivers.

Is it possible for you to learn highway driving without mastering a diesel truck?

Is it possible for you to learn highway driving without mastering a motorcycle?

Is it possible for you to drive a Honda Civic without MASTERING the Honda Civic?

Is there such a thing as "Android Programming"?

If you write a Java Program on a Windows desktop, will the same Java program run on an Android tablet?

Have you written a computer program with any language on any system?

It's possible to write anything without mastering any language it just won't be very efficient.