node_modules are prepared twice on initial run

[rosen-vladimirov]

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: 4.2.4
• Cross-platform modules: Not applicable
• Android Runtime: Not applicable
• iOS Runtime: Not applicable
• Plugin(s): Not applicable, but more visible in case you have a lot of node_modules.

Describe the bug
The first run of the project installs the native platform and prepares node_modules, i.e. copies them to platforms dir. However, this is done twice, which slows down the initial preparation.

To Reproduce

tns create myApp --template tns-template-master-detail-ng
cd myApp
tns run <platform>

No actual way to detect it, but visible when you look at the code.

Expected behavior
Prepare node_modules only once.