Fix compilation. see...

Fix compilation. see https://stackoverflow.com/questions/49162538/running-cordova-build-android-unable-to-find-attribute-androidfontvariation

build-extras.gradle

+configurations.all {
+    resolutionStrategy {
+        force 'com.android.support:support-v4:27.1.0'
+    }
+}

hooks/after_prepare/061_copy_build_extras.js

+#!/usr/bin/env node
+"use strict";
+var fs = require('fs');
+
+// See: https://stackoverflow.com/questions/49162538/running-cordova-build-android-unable-to-find-attribute-androidfontvariation
+
+var rootdir = process.argv[2];
+
+if (rootdir) {
+// go through each of the platform directories that have been prepared
+  var platforms = (process.env.CORDOVA_PLATFORMS ? process.env.CORDOVA_PLATFORMS.split(',') : []);
+
+  for (var x = 0; x < platforms.length; x++) {
+    try {
+      var platform = platforms[x].trim().toLowerCase();
+
+      if (platform == 'android') {
+        var android_dir = rootdir + '/platforms/android';
+        var gradle_file = rootdir + '/build-extras.gradle';
+        var dest_gradle_file = android_dir + '/build-extras.gradle';
+
+        if (fs.existsSync(android_dir) && fs.existsSync(gradle_file)) {
+          console.log('-----------------------------------------');
+          console.log(' Copy ' + gradle_file + ' to ' + android_dir);
+          console.log('-----------------------------------------');
+          fs.createReadStream(gradle_file).pipe(fs.createWriteStream(dest_gradle_file));
+        } else {
+          console.log('-----------------------------------------');
+          console.log( ' File ' + gradle_file + ' not found. Skipping copy to /platforms/android');
+          console.log('-----------------------------------------');
+        }
+      }
+    } catch (e) {
+      process.stdout.write(e);
+    }
+  }
+}
+