Make LenaPi usable on Android devices

- Add app icon
- prevend android device from shutting down cpu while playing music
- fix scaling bug
- fix energy saver for RasPi by reconnecting to music player
- minor refactorings and renaming

LenaPi/controllers/NavigationController.cpp

@@ -3,6 +3,7 @@
 
 #include <QDir>
 #include <QDebug>
+#include <EnergySaver.h>
 
 #include <models/NavigationItemModel.h>
 #include <models/NavigationListModel.h>
@@ -19,6 +20,9 @@ NavigationController::NavigationController(QObject *parent) : QObject(parent),
         mUiState->showNavigation();
         mNavList->navigateTo(item);
     });
+    /* Connect player state to energy saver to prevent device shutdown while playing music.
+     */
+    connect(mMediaPlayer, &MusicPlayer::isPlayingChanged, this, &NavigationController::startOrStopEnergySaverDependingOnPlayerState);
 }
 
 void NavigationController::setDebugOutput(const QString& text)
@@ -111,3 +115,16 @@ void NavigationController::onNavigationRequest()
         mUiState->showMusicPlayer();
     }
 }
+
+void NavigationController::startOrStopEnergySaverDependingOnPlayerState()
+{
+    auto* energySaver = EnergySaver::instance();
+    assert(energySaver);
+    if(energySaver){
+        if(mMediaPlayer->isPlaying()){
+            energySaver->deactivate();
+        } else {
+            energySaver->activate();
+        }
+    }
+}