This removes several references across the code base that depended on the global string constants. Bug: none Change-Id: I007bd4b195c35261039f655f1a8f52e632c3691f Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/335320 Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/main@{#41578}