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: 6.1.0
• Cross-platform modules: 6.1.0
• Android Runtime: 6.1.0
• iOS Runtime: 6.1.0
• Plugin(s):

{
  "nativescript": {
    "id": "org.nativescript.app1",
    "tns-android": {
      "version": "6.1.0"
    },
    "tns-ios": {
      "version": "6.1.0"
    }
  },
  "description": "NativeScript Application",
  "license": "SEE LICENSE IN <your-license-filename>",
  "repository": "<fill-your-repository-here>",
  "dependencies": {
    "nativescript-theme-core": "~1.0.6",
    "nativescript-unit-test-runner": "^0.7.0",
    "tns-core-modules": "~6.1.0"
  },
  "devDependencies": {
    "chai": "4.2.0",
    "karma": "4.3.0",
    "karma-chai": "0.1.0",
    "karma-mocha": "1.3.0",
    "karma-nativescript-launcher": "0.4.0",
    "karma-webpack": "3.0.5",
    "mocha": "6.2.0",
    "nativescript-dev-webpack": "~1.2.0"
  },
  "gitHead": "9475c272a4c74ea6baf24d578bdf46c23a400fea",
  "readme": "NativeScript Application"
}

• Node.js: 10.15.3

Describe the bug
Files with unit tests (located in <project dir>/<app dir>/test are always included in the built application, no matter if tns run or tns test is executed. This increases the size of application as there might be a lot of dev dependencies included in the unit test (for example chai).

To Reproduce

1. Create a new app: tns create app1 --js
2. Navigate to it: cd app1
3. Initialize tests, for example with mocha framework: tns test init --framework mocha
4. Open the generate example.js file and add the following line at the top: const chai = require("chai"); (NOTE: This step is just to show that chai will be included in the built application, you can verify only example.js in step 6)
5. Run tns prepare android - this should not include any test files in the bundle.js
6. Check the generated bundle.js and vendor.js in the platforms directory:

• check the bundle.js - it shouldn't contain any reference to example.js file - in fact it has it
• check the vendor.js - it shouldn't contain any reference to chai - in fact it has it.

Expected behavior
Unit test files and testing dependencies should be included only when tns test <platform> command is executed.

Additional context
This is working correctly in versions prior to 6.0.0.