Email enumeration protection related error and doc updates #8064

Job	Run time
Check changed files	0s
pod-lib-lint-abtesting (iOS)	7m 13s
binary_size_metrics (iOS)	6m 27s
pod-lib-lint-auth (iOS)	6m 37s
pod-lib-lint-dynamiclinks (iOS)	7m 32s
pod-lib-lint-database (iOS)	8m 2s
pod-lib-lint-firestore (iOS)	28m 32s
pod-lib-lint-functions (iOS)	4m 24s
pod-lib-lint-inappmessaging (iOS)	8m 25s
pod-lib-lint-messaging (iOS)	7m 33s
pod-lib-lint-performance (iOS)	10m 20s
pod-lib-lint-remoteconfig (iOS)	11m 18s
pod-lib-lint-storage (iOS)	8m 53s
create_report	3m 8s
	1h 58m 24s

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