Gitaly: support TLS flag for external instances list
Support setting tlsEnabled
individually for external entries.
- add
tlsEnabled
item to theexternal
entries object - Verify this will override
global.gitaly.tls.enabled
- Add specs for this configuration
- Update documentation in charts/globals and advanced/external-gitaly
Other: add example usage to gitlab.boolean.local
Closes #2201 (closed)