Add option to not crop image previews (#2832)

* Don't crop image previews with aspects between 2:1 & 1:2

Fixes #1995

* Custom media preview layout for handling various aspect ratios

app/src/main/java/com/keylesspalace/tusky/adapter/StatusViewHolder.java

@@ -53,11 +53,6 @@ public class StatusViewHolder extends StatusBaseViewHolder {
         contentCollapseButton = itemView.findViewById(R.id.button_toggle_content);
     }
 
-    @Override
-    protected int getMediaPreviewHeight(Context context) {
-        return context.getResources().getDimensionPixelSize(R.dimen.status_media_preview_height);
-    }
-
     @Override
     public void setupWithStatus(@NonNull StatusViewData.Concrete status,
                                 @NonNull final StatusActionListener listener,