At the core of them, there's the same thing: a view that benefits from hardware acceleration when you draw onto it (if the Android version >= 3). Behind the canvas methods, Android uses OpenGL to draw, but in an unoptimized way, so you will get a better performance by using directly OpenGL. BUT to get better results than AS or GV, you will have to master OpenGL and be able to produce good quality code. I don't know if you already looked at it but OpenGL is not for beginners and has a steep learning curve. The Java game engines hide (more or less) the complexity of OpenGL and have a solid framework with good code, so you will achieve greater results with them than with AS or GV. On the contrary, your own code using OpenGL could be very disappointing. Most of the amateurish code using OpenGL that I tested perform equally or less well than AS (usually, less well).
That being said, where are the differences between AS and GV?
GV is very simple and has very limited features (the basic features needed for a simple game). It is game oriented.
AS has an extended set of functions and has no particular orientation. I use it myself in a variety of situations not related to games (as an alternative to ImageView, for example, to have round corners, or to draw a graph). AS lacks some popular functions for games, like the one that animates a spritesheet (and I won't do it because using spritesheets is not a good idea). But you can recreate most needed functions with the existing set.
AS can be seen as an enhanced Canvas library.
For games, AS can offer a slightly superior performance because it provides a fast function to draw a bitmap.
Another difference: AS runs on Android versions < 3 (but without any hardware acceleration).
