I used the rolling template to try launching it on my LG G2 (LGD802) With Android 4.4.2.
As you can see on the screenshot it shows something like the wrong aspect ratio.
I tried the same on my Nexus 10. There the aspect ratio looks okay.
I’ve seen this happen if the device is locked during launch; it gets the resolution of the lock screen instead of the correct window. We have looked at a few ways to automatically unlock the device during launch, but none seems to work for all devices. To prevent this, you may set “Stay Awake” in the Developer options in Settings and check your display timeout. Relaunching the application on the device manually should also show the correct aspect ratio.