Collect BackendTLS Policies

[pleshakov]

As a maintainer of NGF I want to collect the number of used BackendTLS Policies So that I can understand if that feature is used and how many policies are typically deployed.

Acceptance Number of BackendTLSPolicies in use is reported in the product telemetry output

[github-actions[bot]]

Hi @pleshakov!

Thanks for opening this issue! Be sure to check out our Contributing Guidelines and the Issue Lifecycle while you wait for someone on the team to take a look at this.