gradlew not compatible with sh

[armpogart]

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: 5.3.1
• Cross-platform modules: 5.3.1
• Android Runtime: 5.3.1
• iOS Runtime (if applicable):
• Plugin(s):

Describe the bug

tns build android

fails on environment without bash (e.g. Alpine Linux) with the error:

env: can't execute 'bash': No such file or directory
Command ./gradlew failed with exit code 127

I'm not sure where you get gradlew or how you generate it, but gradle itself fixed this issue long time ago and their gradlew is compatible with sh.
The environment is CI build environment with docker and alpine linux image. It wouldn't be problem of course for me install also bash in alpine, but the whole point of using alpine is to keep the size to minimum.

To Reproduce

Expected behavior

Sample project

Additional context

If you give some clues to me where you get gradlew or maybe generate it, I could apply a PR with the fix.

[armpogart]

I'm almost sure that the problem is following gradlew file:
https://github.com/NativeScript/NativeScript/blob/master/tns-core-modules-widgets/android/gradlew

[armpogart]

@vtrifonov I have tested your gradlew file on cli 5.3.1 by replacing the file contents and everything runs perfectly.

Thanks for your quick reaction.