Due to all of the different resolutions and pixel densities available on the Android platform, these Android launch images are best specified as "9-patch" images. More info about 9-patch on Google
Please generate the 9-patch images through the "Splash Screen" option within the "Branding" section of your app's configuration. If you want to provide your own 9-patch images, you may download the Android source code for your app and replace them in the source.
Why does my Android launch image look funny?
The way the Android launch images are generated with the "9-patch images" is that it takes the border colors and stretches them outwards.
If your Android launch image is looking stretched or otherwise not what you expected, we would recommend using a base image that has your desired background color around the entire square border, including the colors. In other words, there should be no other colors that are directing hitting the border of the image.
If this is not clear, or you are still having trouble getting it to work, please contact us and we would be happy to assist further.