blank lines between import groups is ignored

With a format settings file containing

<setting id="org.eclipse.jdt.core.formatter.blank_lines_between_import_groups" value="1"/>

and java.completion.importOrder specifying groups, all imports are still not spaced.

"java.completion.importOrder": [
        "java",
        "javax",
        "org",
        "com",
        "",
        "#"
    ]

Environment

• Operating System: Linux
• JDK version:
• Visual Studio Code version: 1.76
• Java extension version: 1.15.0

Steps To Reproduce

With

import java.time.Duration;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.function.Consumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

2. Format document do not add or remove blank lines

Current Result

import java.time.Duration;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.function.Consumer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

Expected Result

import java.time.Duration;
import java.util.HashSet;
import java.util.Optional;
import java.util.Set;
import java.util.function.Consumer;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

Additional Informations

该 issue 未指定任何 repository 文件或测试。首先，使用提供的 Eclipse formatter 设置、import 顺序和 imports，在 VS Code 中复现 formatter 的行为；当格式化在 java 组和 org 组之间插入一个空行时，fix 即完成。