Imports are not included in the document symbols returned from "getDocumentSymbols" API

Hi

I am writing a vscode extension and I want to get the symbols of a JAVA file.

Environment
Operating System: windows 10
Visual Studio Code version: 1.50.0

Steps To Reproduce
If I run this sample code :

`const vscodeCDSExtension = extensions.getExtension("redhat.java");
const javaDocParams : DocumentSymbolParams = {
textDocument: {
uri: Uri.file(filePath).toString()
}
};

if (vscodeCDSExtension && vscodeCDSExtension.isActive) {
const symbols = await vscodeCDSExtension.exports.getDocumentSymbols(javaDocParams);
console.log(symbols.length);
}`

Current Result
The "imports" of the file are not included in the returned symbols (only "package", classes and methods are returned)

Expected Result
The "imports" also should be included in the result

The JAVA file is attached

CatalogServiceHandler.zip

首先，使用随附的 Java 文件 CatalogServiceHandler.zip 重现 issue 中的 getDocumentSymbols API 调用。跟踪 package、类和方法的返回方式，然后验证 import 声明是否包含在符号结果中；如果 repository 提供了匹配的测试，则添加或更新覆盖率。