Removed unneeded casts to FileDisplayActivity

src/com/owncloud/android/ui/fragment/FileDetailFragment.java

@@ -255,7 +255,7 @@ public class FileDetailFragment extends FileFragment implements
                     ((FileDisplayActivity)mContainerActivity).startDownloadForSending(getFile());
                     
                 } else {
-                    ((FileDisplayActivity)mContainerActivity).getFileOperationsHelper().sendDownloadedFile(getFile());
+                    mContainerActivity.getFileOperationsHelper().sendDownloadedFile(getFile());
                 }
                 return true;
             }

src/com/owncloud/android/ui/fragment/OCFileListFragment.java

@@ -272,7 +272,7 @@ implements EditNameDialogListener, ConfirmationDialogFragmentListener {
                         // media preview
                         ((FileDisplayActivity)mContainerActivity).startMediaPreview(file, 0, true);
                     } else {
-                        ((FileDisplayActivity)mContainerActivity).getFileOperationsHelper().openFile(file);
+                        mContainerActivity.getFileOperationsHelper().openFile(file);
                     }
                     
                 } else {
@@ -390,7 +390,7 @@ implements EditNameDialogListener, ConfirmationDialogFragmentListener {
                     ((FileDisplayActivity)mContainerActivity).startDownloadForSending(mTargetFile);
                     
                 } else {
-                    ((FileDisplayActivity)mContainerActivity).getFileOperationsHelper().sendDownloadedFile(mTargetFile);
+                    mContainerActivity.getFileOperationsHelper().sendDownloadedFile(mTargetFile);
                 }
                 return true;
             }