UpgradeImage in operator blindly upgrades if env var is given.

[hj-johannes-lee]

Is your feature request related to a problem? Please describe.
Currently, when env var is provided (e.g. INTEL_DSA_PLUGIN_SHA=<something>), there is no process for checking about the name of image (the part in the previous example).

Describe the solution you'd like
UpgradeImage should have a process that acts differently than just upgrading to that image:

when the image name in the env var is...

• is not in sha256 form.
• (there may be more, TO BE ADDED)