Fix android zindex issue

Fix android zindex issue

Author: jasonleewj85

src/Drawer.js

@@ -357,14 +357,14 @@ const styles = StyleSheet.create({
     alignItems: 'center',               // center children
     justifyContent: 'flex-end',         // align popup at the bottom
     backgroundColor: 'transparent',     // transparent background
+    elevation: 1,                     // fix android dynamic zindex issue
   },
   // Semi-transparent background below popup
   backdrop: {
     ...StyleSheet.absoluteFillObject,   // fill up all screen
     alignItems: 'center',               // center children
     justifyContent: 'flex-start',       // align popup at the bottom
     backgroundColor: 'black',
-    elevation: 1,                     // fix android dynamic zindex issue
   },
   // Body
   content: {