Update build hook to be compatible with Tabris.js 3.0

The target destination of the google-service.json changed with
Tabris.js 3.0 which is based on cordova-android 7.x.

Author: mpost

scripts/android/copy_google_services.js

@@ -2,16 +2,16 @@
 
 const fs = require('fs');
 
-const ANDROID_PLATFORM = 'platforms/android';
+const APP_MODULE = 'platforms/android/app';
 const GOOGLE_SERVICES_JSON = 'google-services.json';
 
 if (!fs.existsSync(GOOGLE_SERVICES_JSON)) {
   throw new Error(
     'No "google-services.json" file found in /cordova.' +
     'Required by plugin "tabris-plugin-firebase" (Android).');
 } else {
-  if (fs.existsSync(ANDROID_PLATFORM) && fs.statSync(ANDROID_PLATFORM).isDirectory()) {
+  if (fs.existsSync(APP_MODULE) && fs.statSync(APP_MODULE).isDirectory()) {
     fs.createReadStream(GOOGLE_SERVICES_JSON)
-      .pipe(fs.createWriteStream(`${ANDROID_PLATFORM}/${GOOGLE_SERVICES_JSON}`));
+      .pipe(fs.createWriteStream(`${APP_MODULE}/${GOOGLE_SERVICES_JSON}`));
   }
 }