29290 [fuchsia] Add missing protocols to V2 runner. (cla: yes, waiting for tree to go green, platform-fuchsia)

29305 [fuchsia] fidl::InterfaceHandle -> THandle. (cla: yes, platform-fuchsia)

29313 Bump ICU to ece15d049f2d360721716089372e3749fb89e0f4 (cla: yes, platform-fuchsia)

29320 Inform the Dart VM when snapshots are safe to use with madvise(DONTNEED). (platform-ios, platform-android, cla: yes, platform-macos, platform-linux, platform-fuchsia)

29325 [fuchsia] Remove unused SettingsManager protocol (cla: yes, platform-fuchsia)