Don't copy android specific files into the build folder

Don't copy android specific files like java files, manifest file to the android-build folder, and instead just link the path to them in the build.gradle. This will allow users to for example open projects from Android Studio and do modification which will apply to the source files and not the build copy.

This of course can apply only to files that are custom to the user project and not the default files from the Qt installation. Also, this won't apply to files like build.gradle because it's the one that's going to have paths to those files.