Doc: Update Cognito sample Readme to add permissions #1653

Job	Run time
check-codegen-edits	4s
byo-crypto	2m 51s
check-docs	5m 3s
check-submodules	6s
linux-compat (manylinux2014-x64)	5m 30s
linux-compat (manylinux2014-x86)	7m 4s
linux-compat (al2-x64)	7m 6s
linux-compat (alpine-3.16-x64)	9m 56s
linux-compat (alpine-3.16-x86)	9m 58s
linux-compat (alpine-3.16-armv6)	1h 43m 40s
linux-compat (alpine-3.16-armv7)	1h 58m 3s
linux-compat (alpine-3.16-arm64)	1h 42m 48s
linux-compiler-compat (clang-3)	7m 14s
linux-compiler-compat (clang-6)	5m 17s
linux-compiler-compat (clang-8)	7m 2s
linux-compiler-compat (clang-9)	6m 16s
linux-compiler-compat (clang-10)	5m 23s
linux-compiler-compat (clang-11)	5m 19s
linux-compiler-compat (gcc-4.8)	5m 26s
linux-compiler-compat (gcc-5)	5m 19s
linux-compiler-compat (gcc-6)	5m 24s
linux-compiler-compat (gcc-7)	5m 16s
linux-compiler-compat (gcc-8)	6m 12s
linux-github-actions	10m 50s
linux-no-cpu-extensions	6m 51s
linux-smoke-tests	10m 0s
osx	10m 37s
raspberry (raspbian-bullseye)	1h 8m 40s
windows	11m 10s
windows-app-verifier	13m 27s
windows-no-cpu-extensions	12m 5s
windows-vs14 (Win32)	15m 15s
windows-vs14 (x64)	12m 36s
	10h 7m 48s

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