fix(): tcp support

[narmidm]

Description

Adding TCP support for slice Gateway. changes done for gateway cert manager.

Fixes

ovpn/scripts/validate.sh
This code first checks if GATEWAY_PROTOCOL is missing or empty and sets GATEWAY_PROTOCOL to "udp" in that case. If GATEWAY_PROTOCOL is set, it converts it to lowercase using the tr command and then checks if it's not "udp" or "tcp" and sets it to "udp" in that case.

ovpn/template/client-openvpn-combined.conf
ovpn/template/server-openvpn.conf

new configuration added - proto

ovpn/scripts/process.sh
replace the value of from job env value ${GATEWAY_PROTOCOL}.

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• manual testing with using the build image from Jenkins

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 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.

Does this PR introduce a breaking change for other components like kubeslice-controller, worker-operator?

[mridulgain]

Tested OK