I've been looking around for a good set of Android map marker icons (drawables), and I've only seen a few that included a vector image (Illustrator or EPS graphics) so I could customize the icon however I wanted. So, I just created my own icon, saved five common colors to a set of xhdpi, hdpi, mdpi, and ldpi sizes, and posted them to a new repository on GitHub: Android Map Marker Drawables (icons) .
Please see the GitHub repo for more information about the icons, how to use them, and for the original vector image. Here are examples of the icons (in hdpi resolution):





Here's an example app screenshot using a MapView with these icons as the map's Drawable:

Download the entire set of drawables and the original vector artwork from GitHub.