fix(): Added gRPC port configuration & updated sidecar container SecurityContext

[Alokzh]

Description

Added missing ContainerPorts in the sidecar container spec & updated sidecar container SecurityContext

Fixes #361 #362

Changes:

• Added gRPC port configuration (5000) to both server and client sidecar containers
• Updated sidecar container security context with proper capability drops (Drop: ["ALL"])

How Has This Been Tested?

Tested with KubeSlice minimal-demo setup. Verified that Sidecar containrs now properly expose gRPC port (5000) & sidecar container SecurityContext requests only needed permissions

Checklist:

• The title of the PR states what changed and the related issues number (used for the release note).
• Does this PR requires documentation updates?
• I've updated documentation as required by this PR.
• I have ran go fmt
• I have updated the helm chart as required by this PR.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have tested it for all user roles.
• I have added all the required unit test cases.
• I have verified the E2E test cases with new code changes.
• I have added all the required E2E test cases.

Does this PR introduce a breaking change?

[pnavali]

@gourishkb please review the PR.