Fix missing _next folder in Cordova. net::ERR_FILE_NOT_FOUND, file:///android_asset/www/_next/*

build-extras.gradle

// this allows cordova to import folders under _next, which are by default ignored for some reason
// copy this file to platforms/android/build-extras.gradle
// https://stackoverflow.com/questions/9206117/how-to-workaround-autoomitting-fiiles-folders-starting-with-underscore-in/55299304#55299304
// https://issues.apache.org/jira/browse/CB-9448?focusedCommentId=15033508&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-15033508
ext.postBuildExtras = {
  android {
    aaptOptions {
      ignoreAssetsPattern "!._"
    }
  }
}