The SDK is still too immature to think about 2D stuffs like text. I believe you will have to either use 2D quads or switch to 2D overlay.
You might paint a font texture with all necessary characters, then create text geometry on the fly based on input String, each character will be represented by a quad. Make an ortho perspective, and paint the geometry.
You might use onDraw, but currently m5 version supports SurfaceView only, which does not allow onDraw.