Update docker config for OIDC gcr failure

[Aishwarya-Lad]

Change the login to docker login command instead of using the Config struct for OIDC changes.
Made the decision to use login instead of writing file directly.
Why the change was made - The login function integrates with various credential helpers, it also handles different registry specific logic in a better way, as opposed to config write where different registries need to be addressed differently.
It handles any changes in the authentication process across different Docker versions.

What is tested- GCR/ECR/ACR build and push steps with DLC
https://docs.google.com/document/d/1dzLf7PR43NiTjdScxu5gUgWO8O3QTonaDupSDIivFuU/edit