[Help] App force closes and says it has Stopped when implementing "Show external login UI" node?

Hey, I went into the LicenseChecker.java file and i changed the piece of code in the line 149 and saved successfully. I went back to the file to make sure the code was saved and sure enough it was. So i opened up UE4 went to my project and packaged my app. After it was finished packaging I went back to the java file and the packaging made the piece of code in line 149 revert back to the original line of code and I packaged multiple times to see if it still reverts back after changing it back to the new line of code and still reverts back. Even though i saved it reverts back. How do I keep this from happening???

Also when you say TargetSDK. Do you mean the min and target SDk in the android catagory in project settings or SDK and NDK api level in the AndroidSDK category in the project settings when changing to android-19?