gtfsrt: support old way of track change communication #2047

Job	Run time
api-docs	16s
formatting	51s
rsl-ui-checks	42s
macos (macos-x86_64, macos-x86_64-avx)	17m 0s
linux (linux-amd64-avx2-release, linux-amd64)	3m 26s
macos (macos-x86_64-noavx2, macos-x86_64-noavx, On)	27m 25s
linux (linux-amd64-noavx-release, linux-amd64-noavx)	3m 31s
macos (macos-arm64, macos-arm64)	14m 13s
linux (linux-x86-release, linux-x86)	3m 30s
linux (linux-arm-release, linux-arm, qemu-arm-static)	4m 6s
linux (linux-arm64-release, linux-arm64, qemu-aarch64-static)	4m 6s
linux (clang-tidy, true, true)	6m 59s
linux (linux-sanitizer, true)	3m 4s
linux (linux-debug, true, valgrind --leak-check=full --error-exitcode=1)	11m 44s
full-data-set-test (macos-x86_64-noavx2, macos-latest)	59s
full-data-set-test (linux-amd64, ubuntu-20.04)	18s
full-data-set-test (linux-x86, ubuntu-20.04)	29s
full-data-set-test (linux-arm, ubuntu-20.04, qemu-arm-static -L /usr/arm-linux-gnueabihf, bzip2 u...	1m 17s
full-data-set-test (linux-arm64, ubuntu-20.04, qemu-aarch64-static -L /usr/aarch64-linux-gnu, bzi...	1m 47s
docker	48s
	1h 46m 31s

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