explicitly cast var-arg parameter (null) to String[] to get rid of compiler warning

src/main/java/com/owncloud/android/datamodel/UploadsStorageManager.java

@@ -272,7 +272,7 @@ public class UploadsStorageManager extends Observable {
     }
 
     public OCUpload[] getAllStoredUploads() {
-        return getUploads(null, null);
+        return getUploads(null, (String[]) null);
     }
 
     private OCUpload[] getUploads(@Nullable String selection, @Nullable String... selectionArgs) {
@@ -393,7 +393,7 @@ public class UploadsStorageManager extends Observable {
      */
     public OCUpload[] getFinishedUploads() {
 
-        return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_SUCCEEDED.value, null);
+        return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_SUCCEEDED.value, (String[]) null);
     }
 
     public OCUpload[] getFailedButNotDelayedUploadsForCurrentAccount() {
@@ -432,7 +432,7 @@ public class UploadsStorageManager extends Observable {
                         "<>" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
                         AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
                         "<>" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue(),
-                null
+                (String[]) null
         );
     }
 

src/main/java/com/owncloud/android/providers/FileContentProvider.java

@@ -175,14 +175,14 @@ public class FileContentProvider extends ContentProvider {
                                 db,
                                 ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_DIR, childId),
                                 null,
-                                null
+                                (String[]) null
                         );
                     } else {
                         count += delete(
                                 db,
                                 ContentUris.withAppendedId(ProviderTableMeta.CONTENT_URI_FILE, childId),
                                 null,
-                                null
+                                (String[]) null
                         );
                     }
                     children.moveToNext();