DeployConfigurationFactory: Properly extract the abstract class

Make DeployConfigurationFactory a true base class. Introduce the
DefaultDeployConfigurationFactory as the implementation that
actually creates DefaultDeployConfigurations.

This mostly moves code around. The virtual canHandle method was
mostly unused and was removed from most classes.

Change-Id: I170d94c648e67f3fe52a76ffb5344f389ae49efc
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/plugins/android/androiddeployconfiguration.cpp

@@ -135,10 +135,5 @@ QString AndroidDeployConfigurationFactory::displayNameForId(Core::Id id) const
     return QString();
 }
 
-bool AndroidDeployConfigurationFactory::canHandle(Target *parent) const
-{
-    return AndroidManager::supportsAndroid(parent);
-}
-
 } // namespace Internal
 } // namespace Android