[Platform API]: Update test cases to make use of capabilities fields in platform.json#4332

Blueve merged 2 commits intosonic-net:mastersonic-net/sonic-mgmt:masterfrom

ArunSaravananBalachandran:platform_json_capabilitiesArunSaravananBalachandran/sonic-mgmt:platform_json_capabilitiesCopy head branch name to clipboard