Inject code to load App Shielding

After the App Shielding libraries and Java-code have been included in the app, the app code itself needs to be modified in order to ensure App Shielding is loaded and started. App Shielding should be loaded and started as early as possible in order to enforce the security policy which it is configured for as soon as possible, and this will require changes to several classes, and may require changes to the AndroidManifest.xml.

First of all, if the application does not provide any custom android.os.Application class, then the no.promon.shield.AppMonitor class will be set as the main application class in the manifest.

Several of the classes of the app will be modified by changing the class initializer method <clinit>. If these classes do not have a class initializer method, then one is created. The method will make sure that a call to
no.promon.shield.LibStarter is performed first. The classes that will have this code injected are described in Binding.