Android: Improve "Add new AVD" dialog

* Re-organize the implementation to create a new AVD
* Use SystemImage instead of SdKPlatform because now
an SdkPlatform can be installed partially with a SystemImage.
The current implementation does not consider the this case,
thus we end up with an uncomplete list of installed system images.
* Add Device definitions with categories (phone, tablet, tv, etc.)
to the creation process (check -d arg in avdmanager create avd).

Task-number: QTCREATORBUG-23284
Change-Id: Id02a71ad452fb423fa2781d06ef3fcf2afa328a9
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/android/androidsdkmanager.h

@@ -69,6 +69,7 @@ public:
     const AndroidSdkPackageList &allSdkPackages();
     AndroidSdkPackageList availableSdkPackages();
     AndroidSdkPackageList installedSdkPackages();
+    SystemImageList installedSystemImages();
 
     SdkPlatform *latestAndroidSdkPlatform(AndroidSdkPackage::PackageState state
                                           = AndroidSdkPackage::Installed);