Add Recaptcha App Check Provider stubs #7748

Job	Run time
prepare_matrix	5s
local-integration-tests-linux-openssl	22m 29s
macos-15-Release-arm64-static	23m 31s
ubuntu-22.04-Debug-x64-static	34m 22s
ubuntu-22.04-Release-x86-static	38m 42s
ubuntu-22.04-Debug-x86-static	38m 48s
ubuntu-22.04-Release-x64-static	34m 31s
windows-latest-Debug-x86-dynamic	49m 49s
macos-15-Debug-arm64-static	16m 46s
windows-latest-Release-x64-static	52m 20s
	5h 11m 23s

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