Defining Z order of views of RelativeLayout in Android
Solution 1:
The easiest way is simply to pay attention to the order in which the Views are added to your XML file. Lower down in the file means higher up in the Z-axis.
Edit: This is documented here and here on the Android developer site. (Thanks @flightplanner)
Solution 2:
If you want to do this in code you can do
View.bringToFront();
see docs