Lazy routes of Angular apps with custom paths not found in preview

[DimitarTachev]

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: 5.1.1
• Cross-platform modules: 5.1.0

Describe the bug
When the app.module is imported from a module which has to be resolved based on the Typescript config paths (e.g. @scr/app/app.module), the webpack build is not generating any lazy chunks in preview and the app crashes runtime.

To Reproduce

1. Create an Angular app with lazy routes (e.g. use our tabs template)
2. Edit the tsconfig and add some custom paths. (e.g. "paths": { "@src/*": [ "src/*.android.ts", "src/*.ios.ts", "src/*.tns.ts", "src/*.web.ts", "src/*" ] })
3. Edit your main.ts file and import the app module using the custom paths (e.g. import { AppModule } from '@src/app/app.module';)
4. Preview the app using tns preview --bundle

Expected behavior
We should be able to generate lazy chunks even when the app module is imported from a custom path.