ProjectExplorer: Make kit aspects self-register

Also, construct the KitManager implicitly when the first
KitAspect is created. Ramp-down is still explicit and
somewhat odd.

Change-Id: If1506e1d0789ecabbaad2d8008851d0b42c5218b
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/android/androidplugin.cpp

@@ -136,6 +136,7 @@ public:
     AndroidManifestEditorFactory manifestEditorFactory;
     AndroidRunConfigurationFactory runConfigFactory;
     AndroidBuildApkStepFactory buildApkStepFactory;
+    AndroidGdbServerKitAspect gdbServerKitAspect;
 };
 
 AndroidPlugin::~AndroidPlugin()
@@ -160,8 +161,6 @@ bool AndroidPlugin::initialize(const QStringList &arguments, QString *errorMessa
 
     d = new AndroidPluginPrivate;
 
-    KitManager::registerKitAspect<Internal::AndroidGdbServerKitAspect>();
-
     connect(KitManager::instance(), &KitManager::kitsLoaded,
             this, &AndroidPlugin::kitsRestored);