fix(py-sdk): lowercase gRPC metadata headers for Python compatibility - #359

Steps involved in Meesho's Auto CICD:

CI (Continuous Integration) Steps:
1. Validation Stage
	1.1 Branch validation: Is raised against the correct branch or correct source branch
	1.2 Config validation: config.yaml file schema is correct
	1.3 Deployment validation: Is only deployment file change -> Skip CI
	1.4 CAC validation: Is only CAC change -> Skip CI for other envs
	1.5 Modules validation: Production modules are present in staging (for staging environment)
	1.6 Cron deployables validation: Cron deployables are present in staging (for staging environment)
2. Jenkins Build
	2.1 Artifact Build
	2.2 MQ Library version check -> Only Java apps
	2.3 CAC schema validation
	2.4 Test
	2.5 Code Coverage
	2.6 Docker Build & Push
	2.7 Upload Artifact to Registry -> Only Java apps
	2.8 Cache invalidation -> Only Nodejs apps

CD (Continuous Deployment) Steps:
3. Validation Stage
	3.1 Validate deployment.yaml file schema
	3.2 Validate values_properties.yaml file schema
4. Generate values.yaml files
	4.1 Process deployment configuration
	4.2 Generate templated values files
	4.3 Commit helm values files to repository
5. ArgoCD Application Deployment
	5.1 Refresh ArgoCD application
	5.2 Sync ArgoCD application
	5.3 Multi-zone deployment (if enabled)
6. Verify deployment and health
	6.1 Check sync status
	6.2 Verify application health

Notes:
	- For "hotfix_... -> main" PRs, all steps are skipped (Also it's tracked centrally in Kiazen meetings)
	- For "ftr -> develop" PRs, only CI steps (1-2) are executed, CD steps (3-5) are skipped.
	- For direct pre-prod release use "pre-prod_... -> main" PRs and get it whitelisted by @devops-oncall with manager approval
	- For pre-prod release, it cannot be merged to main, it can only be deployed to pre-prod

Incase of any issues, please refer to the https://meesho.atlassian.net/wiki/spaces/DEVOPS/pages/4296114377.
Only reach out to the @devops-oncall in #devops-tech channel after referring the FAQs.