Revert "adjust screen scale for some ios devices"

Runtime/Plugins/platform/ios/DeviceScreen.mm

 #import <UIKit/UIKit.h>
-#import "UIWidgetsDevice.h"
-    float IOSDeviceScaleFactor()
+    int IOSDeviceScaleFactor()
-        float scale = [[UIScreen mainScreen] scale] * 1.0;
-        if ([UIWidgetsDevice NeedScreenDownSample]) {
-            scale *= 0.8696;
-        }
-        return scale;
+        return [[UIScreen mainScreen] scale];
     }
 }

Runtime/engine/DisplayMetrics.cs

 
 #if UNITY_IOS
         [DllImport("__Internal")]
-        static extern float IOSDeviceScaleFactor();
+        static extern int IOSDeviceScaleFactor();
 
 		[DllImport("__Internal")]
 		static extern viewMetrics IOSGetViewportPadding();