So the question do you want to target Android Market only or Android + Java?
If you are an experienced Java developer, I would say mention your experience as Java developer and then add your experience as an Android developer. Try to indicate that you are making a shift. This way you will have a professional experience as well as your own project to indicate you are trying to make switch. Three projects are good enough to get into Android Market. Even one is good enough. You just have to sell yourself. I probably would list them on the top since that is where I am focusing now.
I had a similar change of career from C++ development to web development. Initially I had listed only one of my PHP projects and my resume was a mixture of C++ and PHP. Gradually got a couple of more projects that I added and then I just totally focused it on Web Development. I still mentioned my C++ experience. I had better success with my web developer resume although the C++ market wasn't that bad at all.
Should you list your personal project?
Absolutely. As Justin answer says if you are proud of it, mention it! You must! Believe it or not I got sold by stuff that I did personally years ago when I was a student. I was proud of it so I mentioned it. One could have said, why bother mentioning such thing, and they wouldn't be that wrong.
I think it is important to highlight both your experiences Java + Android. And you are good to go.