Change link script and related file

When install in RN > 0.30 the link script will automatically add a
statement to Android HTTP response callback (in RNFetchBlobReq.java) so
that response body does not leaking.

Author: wkh237

src/android/src/main/java/com/RNFetchBlob/RNFetchBlobReq.java

@@ -451,7 +451,7 @@ private void done(Response resp) {
                 break;
         }
         removeTaskInfo();
-//        resp.close();
+        resp.close();
     }
 
     /**

src/scripts/prelink.js

@@ -45,6 +45,15 @@ if(VERSION < 0.28) {
   console.log('adding OkHttp3 dependency to pre 0.28 project .. ok')
 }
 
+if(VERSION > 0.30) {
+  let dest = process.cwd() + '/node_modules/react-native-fetch-blob/android/src/main/java/com/RNFetchBlob/RNFetchBlobReq.java'
+  var main = fs.readFileSync(dest);
+  console.log('patching OkHttp3 3.4.1 API ..')
+  main = String(main).replace('// ${OKHTTP 3.4.1 ONLY STATEMENT}', "resp.close();");
+  fs.writeFileSync(dest, main);
+  console.log('patching OkHttp3 3.4.1 API .. ok')
+}
+
 // set file access permission for Android < 6.0
 fs.readFile(MANIFEST_PATH, function(err, data) {