Fix "failed to stat path null" on Android

Author: flyskywhy

FileReader.js

@@ -344,6 +344,11 @@
         // https://github.com/RonRadtke/react-native-blob-util/issues/117
         path = decodeURIComponent(path);
 
+        // Android need this otherwise startsWith "content://com.android.externalstorage.documents/document/primary:..." will
+        // `failed to stat path "null"
+        // because it does not exist or it is not a folder` as err.message
+        path = path.replace(/^content:\/\/com.android.externalstorage.documents\/document\/primary:/, '/sdcard/');
+
         fs.stat(path).then(function(stat) {
           file.lastModified = stat.lastModified;
           file.lastModifiedDate = new Date(stat.lastModified);