feat(parametermanager): Added samples for kms_key field in regional parameter

[durgesh-ninave-crest]

Description

Added samples for kms_key field in regional parameter using Parameter manager SDK

Sample List (regional):

1. create_regional_param_with_kms_key
2. update_regional_param_kms_key
3. remove_regional_param_kms_key

Added required Tests for the same.

Checklist

• [X] I have followed Sample Format Guide
• [X] pom.xml parent set to latest shared-configuration
• [X] Appropriate changes to README are included in PR
• [X] These samples need a new API enabled in testing projects to pass (let us know which ones)
• [X] These samples need a new/updated env vars in testing projects set to pass (let us know which ones)
• [X] Tests pass: mvn clean verify required
• [X] Lint passes: mvn -P lint checkstyle:check required
• [ ] Static Analysis: mvn -P lint clean compile pmd:cpd-check spotbugs:check advisory only
• [X] This sample adds a new sample directory, and I updated the CODEOWNERS file with the codeowners for this sample
• [X] This sample adds a new Product API, and I updated the Blunderbuss issue/PR auto-assigner with the codeowners for this sample
• [X] Please merge this PR for me once it is approved