chore(core): add validation checks for AmplifyOutputs Json deserialization #3134

Job	Run time
test / test-dart-vm (3.3.0)	2m 22s
test / test-dart-vm (stable)	2m 6s
ddc_test / test-dart-ddc (3.3.0, chrome)	3m 30s
ddc_test / test-dart-ddc (3.3.0, firefox)	3m 54s
dart2js_test / test-dart-2js (3.3.0, chrome)	4m 6s
native_test / test-dart-native (macos-14)	2m 2s
ddc_test / test-dart-ddc (stable, chrome)	3m 37s
dart2js_test / test-dart-2js (3.3.0, firefox)	4m 28s
native_test / test-dart-native (windows-latest)	4m 34s
ddc_test / test-dart-ddc (stable, firefox)	3m 48s
dart2js_test / test-dart-2js (stable, chrome)	3m 45s
dart2js_test / test-dart-2js (stable, firefox)	4m 9s
	42m 21s

Provide feedback