Fix tns update command when no platform is added

[Fatme]

In case when no platform is added and tns update android command is executed, The platform android is not added to this project error is thrown.

Steps to reproduce:

1. tns create TestApp
2. tns platform update android (now installs 4.0.1)

PR Checklist

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• Tests for the changes are included.

[dtopuzov]

run ci

[Natalia-Hristova]

issue: #3632