Update dependency react-navigation to v4

Author: renovate-bot

package.json

@@ -30,6 +30,6 @@
     "react": "16.9.0",
     "react-native": "0.60.5",
     "react-native-gifted-chat": "0.9.11",
-    "react-navigation": "3.11.1"
+    "react-navigation": "4.4.4"
   }
 }