Testing broken: webpack 4 vs webpack 3 requirement by karma-webpack 3.0.5

首先，使用列出的 ns create、ns test init --framework mocha 和 ns test android 命令复现该问题。检查 karma-webpack 3.0.5 和 @nativescript/webpack 4.0.0 的要求；示例测试能够在没有 webpack 预处理错误的情况下运行即表示完成。

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):

✔ Component nativescript has 7.1.2 version and is up to date.
✔ Component @nativescript/core has 7.1.2 version and is up to date.
✖ Component @nativescript/ios is not installed.
✔ Component @nativescript/android has 7.0.1 version and is up to date

Describe the bug

ns test android fails with this karma error:
ERROR [preprocess]: Can not load "webpack"!
Because webpack 3 can't be installed side by side with webpack 4 (afaik?!). npm install correctly states that the peer dependency for webpack 3 (required by karma-webpack@3.0.5) needs to be installed manually.

  "dependencies": {
    "@nativescript/core": "~7.1.0",
    "@nativescript/theme": "~2.3.0",
    "@nativescript/unit-test-runner": "^1.0.2"
  },
  "devDependencies": {
    "@nativescript/android": "7.0.1",
    "@nativescript/webpack": "~4.0.0",
    "@types/karma-chai": "0.1.2",
    "@types/mocha": "8.2.0",
    "chai": "4.2.0",
    "karma": "6.0.0",
    "karma-chai": "0.1.0",
    "karma-mocha": "2.0.1",
    "karma-nativescript-launcher": "0.4.0",
    "karma-webpack": "3.0.5",
    "mocha": "8.2.1",
    "typescript": "~3.9.0"
  },

To Reproduce

ns create karmaissue --template @nativescript/template-blank-ts@7.0.4
cd karmaissue
ns test init --framework mocha
ns test android

Expected behavior
Sample test runs (karma doesn't throw an error)