Rename event parameter (#3782)

## Description

This PR renames `event` parameter to `ev` in order to remove compilation
warning.

If #3738 has not been fixed yet - this one should do the trick.

## Test plan

Build example app on android

Author: m-bert

packages/react-native-gesture-handler/android/src/main/java/com/swmansion/gesturehandler/react/RNGestureHandlerRootView.kt

@@ -40,11 +40,11 @@ class RNGestureHandlerRootView(context: Context?) : ReactViewGroup(context) {
     super.dispatchTouchEvent(event)
   }
 
-  override fun dispatchGenericMotionEvent(event: MotionEvent) =
-    if (rootViewEnabled && rootHelper!!.dispatchTouchEvent(event)) {
+  override fun dispatchGenericMotionEvent(ev: MotionEvent) =
+    if (rootViewEnabled && rootHelper!!.dispatchTouchEvent(ev)) {
       true
     } else {
-      super.dispatchGenericMotionEvent(event)
+      super.dispatchGenericMotionEvent(ev)
     }
 
   override fun requestDisallowInterceptTouchEvent(disallowIntercept: Boolean) {