Fix unpack function call in scripts

[GetmanetsIrina]

ATF Test Scripts to fix #2692

This PR is ready for review.

Summary

Update unpack function call

ATF version

latest

Changelog

• Fixed wrong usage of unpack function
• Updated unpack to table.unpack because Changes in the Lua Libraries 5.2: Function unpack was moved into the table library and therefore must be called as table.unpack.

CLA

• [x] I have signed the CLA

[GetmanetsIrina]

@theresalech, this PR is ready for Livio review.

[theresalech]

@GetmanetsIrina, thank you! Can you please link the issue resolved by this PR?

[GetmanetsIrina]

@theresalech, PR is linked with https://github.com/smartdevicelink/sdl_atf_test_scripts/issues/2692