Fix places that trigger no-unused-lambda-capture - change to using static-constexpr.

Follow up on https://codereview.webrtc.org/3005433002/.

BUG=webrtc:7133
TBR=stefan@webrtc.org

Review-Url: https://codereview.webrtc.org/3003723002
Cr-Original-Commit-Position: refs/heads/master@{#19499}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 05b07bb833328515f7e86b769a7660008f0f498e
5 files changed