Android: Decouple missing packages logic from UI

There is no need to modify UI selection in order to
execute installation / deinstallation.

Change-Id: I205477e5ff0e7b07bfbcd6b5f8f985fcb180884e
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/android/androidsdkmodel.h

@@ -41,9 +41,8 @@ public:
     Qt::ItemFlags flags(const QModelIndex &index) const override;
     bool setData(const QModelIndex &index, const QVariant &value, int role) override;
 
-    QStringList selectMissingEssentials();
-    QList<const AndroidSdkPackage *> userSelection() const;
     void resetSelection();
+    InstallationChange installationChange() const;
 
 private:
     void clearContainers();