Export setupContext publically to be used by additional contexts. #10211

Job	Run time
labels / InternalPRRequired	1s
lint / bazel	1m 53s
fixup / block-fixup	5s
test (linux, ubuntu-20.04) / bazel	2m 31s
test (linux, ubuntu-20.04, -asan) / bazel	2m 0s
test (linux, ubuntu-20.04, -debug) / bazel	2m 10s
test (macOS, macos-15) / bazel	2m 40s
test (windows, windows-2022) / bazel	17m 48s
	29m 8s

Provide feedback