Implementing native android .aar file or .aidl in Nativescript throws native calss object without access to methods

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI:
• Cross-platform modules:
• Android Runtime:
• iOS Runtime:
• Plugin(s):
  Android
  Describe the bug

I have an Android SDk done with java whic I already converted to .aar file. I created a plugin and placed the aar file in App_Resources/Android/libs directory. In my index.js file, I have this

var intent = new android.content.Intent(application.android.foregroundActivity, com.iposprinter.printertestdemo.IPosPrinterTestDemo.class)
intent.setFlags(android.content.Intent.FLAG_ACTIVITY_NEW_TASK);
application.android.foregroundActivity.startActivity(intent);

This cause the sdk to display.

Doing this

var iposprinter=new com.iposprinter.printertestdemo.IPosPrinterTestDemo()
console.log(iposprinter) //outputs com.iposprinter.printertestdemo.IPosPrinterTestDemo@682890e
while this `console.log(iposprinter.printerInit) outputs undefined`

while this

`console.log(iposprinter.printerInit) outputs undefined`
console.log(iposprinter.printerInit()) outputs undefined
TypeError: iposprinter.printerInit is not a function

How do I call methods from this package?
To Reproduce

Expected behavior

Sample project

Additional context

先从插件的 index.js 和 App_Resources/Android/libs 下的 .aar 放置位置开始，然后重现 issue 中的 native object 和 printerInit 日志。检查 Android runtime 如何公开已打包的 Java class；当 SDK 方法可用并且能够在不出现 TypeError 的情况下调用时，即表示完成。