[1.28] google_grpc: add a runtime flag to disable TLSv1.3

[kyessenov]

Backport of #32315

[repokitteh-read-only]

CC @envoyproxy/coverage-shephards: FYI only for changes made to (test/per_file_coverage.sh).
envoyproxy/coverage-shephards assignee is @alyssawilk
CC @envoyproxy/runtime-guard-changes: FYI only for changes made to (source/common/runtime/runtime_features.cc).
CC @envoyproxy/dependency-shepherds: Your approval is needed for changes made to (bazel/.*repos.*\.bzl)|(bazel/dependency_imports\.bzl)|(api/bazel/.*\.bzl)|(.*/requirements\.txt)|(.*\.patch).
envoyproxy/dependency-shepherds assignee is @htuch

🐱

Caused by: #32533 was opened by kyessenov.

see: more, trace.