fix: don't enable overlay on iOS by default

Author: satya164

src/navigators/__tests__/__snapshots__/NestedNavigator.test.tsx.snap

@@ -71,24 +71,6 @@ Array [
           }
         }
       >
-        <View
-          pointerEvents="none"
-          style={
-            Array [
-              Object {
-                "backgroundColor": "#000",
-                "bottom": 0,
-                "left": 0,
-                "position": "absolute",
-                "right": 0,
-                "top": 0,
-              },
-              Object {
-                "opacity": undefined,
-              },
-            ]
-          }
-        />
         <View
           pointerEvents="box-none"
           style={
@@ -245,24 +227,6 @@ Array [
                         }
                       }
                     >
-                      <View
-                        pointerEvents="none"
-                        style={
-                          Array [
-                            Object {
-                              "backgroundColor": "#000",
-                              "bottom": 0,
-                              "left": 0,
-                              "position": "absolute",
-                              "right": 0,
-                              "top": 0,
-                            },
-                            Object {
-                              "opacity": undefined,
-                            },
-                          ]
-                        }
-                      />
                       <View
                         pointerEvents="box-none"
                         style={

src/navigators/__tests__/__snapshots__/StackNavigator.test.tsx.snap

@@ -71,24 +71,6 @@ Array [
           }
         }
       >
-        <View
-          pointerEvents="none"
-          style={
-            Array [
-              Object {
-                "backgroundColor": "#000",
-                "bottom": 0,
-                "left": 0,
-                "position": "absolute",
-                "right": 0,
-                "top": 0,
-              },
-              Object {
-                "opacity": undefined,
-              },
-            ]
-          }
-        />
         <View
           pointerEvents="box-none"
           style={
@@ -407,24 +389,6 @@ Array [
           }
         }
       >
-        <View
-          pointerEvents="none"
-          style={
-            Array [
-              Object {
-                "backgroundColor": "#000",
-                "bottom": 0,
-                "left": 0,
-                "position": "absolute",
-                "right": 0,
-                "top": 0,
-              },
-              Object {
-                "opacity": undefined,
-              },
-            ]
-          }
-        />
         <View
           pointerEvents="box-none"
           style={

src/views/Stack/Card.tsx

@@ -6,6 +6,7 @@ import {
   ViewProps,
   StyleProp,
   ViewStyle,
+  Platform,
 } from 'react-native';
 import Animated from 'react-native-reanimated';
 import {
@@ -94,7 +95,7 @@ const {
 
 export default class Card extends React.Component<Props> {
   static defaultProps = {
-    overlayEnabled: true,
+    overlayEnabled: Platform.OS !== 'ios',
     shadowEnabled: true,
     gesturesEnabled: true,
   };