Change artwork upload to sets to avoid duplicates

Author: Henigan

android/sdl_android/src/androidTest/java/com/smartdevicelink/managers/screen/choiceset/PreloadPresentChoicesOperationTests.java

@@ -169,7 +169,7 @@ public void setUpEmptyWindowCapability() {
 
     @Test
     public void testArtworksToUpload() {
-        List<SdlArtwork> artworksToUpload = preloadChoicesOperation.artworksToUpload();
+        HashSet<SdlArtwork> artworksToUpload = preloadChoicesOperation.artworksToUpload();
         assertNotNull(artworksToUpload);
         assertEquals(artworksToUpload.size(), 1);
     }

base/src/main/java/com/smartdevicelink/managers/screen/choiceset/PreloadPresentChoicesOperation.java

@@ -255,7 +255,7 @@ public void onComplete(boolean success) {
     private void preloadCellArtworks(@NonNull final CompletionListener listener) {
         this.currentState = SDLPreloadPresentChoicesOperationState.UPLOADING_IMAGES;
 
-        List<SdlArtwork> artworksToUpload = artworksToUpload();
+        List<SdlArtwork> artworksToUpload = new ArrayList<>(artworksToUpload());
 
         if (artworksToUpload.size() == 0) {
             DebugTool.logInfo(TAG, "Choice Preload: No Choice Artworks to upload");
@@ -850,8 +850,8 @@ public void setLoadedCells(HashSet<ChoiceCell> loadedCells) {
         this.loadedCells = loadedCells;
     }
 
-    List<SdlArtwork> artworksToUpload() {
-        List<SdlArtwork> artworksToUpload = new ArrayList<>();
+    HashSet<SdlArtwork> artworksToUpload() {
+        HashSet<SdlArtwork> artworksToUpload = new HashSet<>();
         for (ChoiceCell cell : cellsToUpload) {
             if (shouldSendChoicePrimaryImage() && fileManager.get() != null && fileManager.get().fileNeedsUpload(cell.getArtwork())) {
                 artworksToUpload.add(cell.getArtwork());