remove unused param from function (#3039)

docs/screen-api.md

 });
 ```
 
-## dismissLightBox(params = {})
+## dismissLightBox()
 
 Dismiss the current lightbox.
 

docs/top-level-api.md

 });
 ```
 
-## dismissLightBox(params = {})
+## dismissLightBox()
 
 Dismiss the current lightbox.
 

src/Navigation.js

   return platformSpecific.showLightBox(params);
 }
 
-function dismissLightBox(params = {}) {
-  return platformSpecific.dismissLightBox(params);
+function dismissLightBox() {
+  return platformSpecific.dismissLightBox();
 }
 
 function showInAppNotification(params = {}) {

src/Screen.js

     return Navigation.showLightBox(params);
   }
 
-  dismissLightBox(params = {}) {
-    return Navigation.dismissLightBox(params);
+  dismissLightBox() {
+    return Navigation.dismissLightBox();
   }
 
   showInAppNotification(params = {}) {

src/deprecated/platformSpecificDeprecated.ios.js

   });
 }
 
-function dismissLightBox(params) {
+function dismissLightBox() {
   Modal.dismissLightBox();
 }