Description
There was a sonic-buildimage issue reported (sonic-net/sonic-buildimage#8032) which is about a failure when we install a new version of master image - with the DUT already running master. sonic_installer install command works fine when upgrading from older version like 201811/201911 --> a master image

So it is good to add a test to cover this scenario of sonic_install between same version, like master --> master.

Steps to reproduce the issue:

1. Install a sonic-buildimage public/master based image on a DUT
2. reboot the DUT and make sure it is running with that master image
3. Do another sonic_installer install to upgrade to a newer version of master image itself, there is failure seen as mentioned in Image installation failure caused by sonic-package-manager sonic-buildimage#8032

Describe the results you received:
Errors as reported in sonic-net/sonic-buildimage#8032

Describe the results you expected:
Should install the new version master image with the sonic_installer command.