Parse lightbox backgroundColor from style

src/deprecated/platformSpecificDeprecated.android.js

   const backgroundBlur = _.get(params, 'style.backgroundBlur');
   const backgroundColor = _.get(params, 'style.backgroundColor');
   if (backgroundColor) {
-    params.backgroundColor = processColor(params.backgroundColor);
+    params.backgroundColor = processColor(backgroundColor);
   } else {
     if (backgroundBlur === 'dark') {
       params.backgroundColor = processColor('rgba(0, 0, 0, 0.5)');