Fix resource name mismatch in application update test

[prathameshk03]

Problem

test_application_update generated different resource names for the initial and replica update manifests

As a result, kubectl replace attempts to update a HelloWorldService that was never created and fails with a NotFound error.

Fix

Allow _process_template() to accept an optional resource name and reuse the original hs1_name when generating the replicas update manifest.

This ensures both manifests refer to the same HelloWorldService resource.