TF-2.16 test modification and handling

[shantanutrip]

Issue #, if available:

Description of changes:
TF-2.16 test modification and handling: For TF2.16 DLCs, we have TF2.16.2 training and TF2.16.1 inference images. The counterparts for both of them do not exist which is by-default assumed by the test suite. This causes failures.

TF images do not have a 1:1 connection between training and TF-Serving versions anymore, thus, we have to handle this for TF2.16 images.

To handle this, in Tensorflow Estimator, we just use the major.minor version for TF 2.16.* images when retrieving the image_uri.

This is being handled on the test side by making the tf_full_version point to TF2.16 to ensure tests that use fit and deploy using the same estimator do not fail.

Testing done:
CICD

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[arjkesh]

Nit: you can prob just assign a variable for the version object so you don't have to reinstantiate multiple times

[shantanutrip]

Thanks, made the change

[arjkesh]

LGTM