Defect: ATF doed not parse structure like '"menuIcon" : null'

[GetmanetsIrina]

Summary

ATF doed not parse structure like '"menuIcon" : null'

Steps to reproduce

1. Register and activate mobile app
2. Request AddSubMenu without menuIcon
   Script for reproduce Added check of the menuIcon parameter absence sdl_atf_test_scripts#2142

Expected result

SDL sends "menuIcon" : null in UI.AddSubmenu to HMI, ATF parse "menuIcon" : null and fail test with message "SDL sends menuIcon in request to HMI in case parameter is absent in request"

Actual result

In case SDL sends message like

 {
   "params" : {
      "appID" : 1676936826,
      "menuID" : 1000,
      "menuIcon" : null,
      "menuParams" : {
         "menuName" : "SubMenupositive",
         "position" : 500
      }
   }
}

ATF will parse it like

[appID]: 814596906
[menuID]: 1000
[menuParams]: {
    [menuName]: 'SubMenupositive'
    [position]: 500
}

So atf tests will not failed with error because of redundant null parameter.

Can be reproduced in case SDL defect smartdevicelink/sdl_core#2744 is reproduced.