[Vertex AI] Add integration tests for App Check failure #729

Job	Run time
pod-lib-lint (ios, macos-14)	5m 58s
spm-package-resolved	55s
testapp-integration (iOS, macos-15)	3m 13s
spm-unit (macos-13, Xcode_15.2, iOS)	6m 18s
sample (macos-13, Xcode_15.2)	3m 45s
spm-unit (macos-14, Xcode_15.4, iOS)	6m 6s
sample (macos-14, Xcode_15.4)	2m 31s
spm-unit (macos-15, Xcode_16, iOS)	2m 2s
sample (macos-15, Xcode_16)	1m 45s
spm-unit (macos-15, Xcode_16, tvOS)	1m 43s
spm-unit (macos-15, Xcode_16, macOS)	1m 29s
spm-unit (macos-15, Xcode_16, watchOS)	1m 37s
spm-unit (macos-15, Xcode_16, catalyst)	1m 40s
spm-unit (macos-15, Xcode_16, visionOS)	1m 49s
	40m 51s

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