runconfig: consolidate createConfigurationWidget implementations

Most derived classes used essentially identical 'return 0;'
implementations. Use a base class implementation doing that instead.

Change-Id: I99727ac2230a5d9f168b4b0eb5927f8efff44e64
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/android/androidrunfactories.cpp

@@ -190,11 +190,5 @@ QString AndroidRunControlFactory::displayName() const
     return tr("Run on Android device/emulator");
 }
 
-RunConfigWidget *AndroidRunControlFactory::createConfigurationWidget(RunConfiguration *config)
-{
-    Q_UNUSED(config)
-    return 0;
-}
-
 } // namespace Internal
 } // namespace Qt4ProjectManager