I definitely agree with techb, and what has been said so far.
again here are the important things:
-If you know java, it is easy.
-If you want to create a game use a already development game engine like libgdx or andEngine according on what you want to do, if you want 3d, use unity, except it is kind of expense if I remember right.
-The "hardest" part about android game development is dealing with all the different screen sizes and resolutions of all the android phones out there, that is why using a android game engine is highly recommended.
also, if you can figure it out, I would recommend mybringback tutorials, or the tutorials he did for thenewboston (if you like video tutorials) if you like reading, there are a lot of blog post and open source projects you can easily find what you are looking for.
good luck,
Dwolf