Atest: checking input test reference to avoid exceptions.

Add a check of colon in test reference.

BUG: 235542838

Test: atest --no-bazel-mode CtsVoiceInteractionTestCases:HotwordDetectionServiceBasicTest:testHotwordDetectionService_onDetectFromExternalSource_rejected
Change-Id: If72545d4b2c47b18d9ed4d7fbc4242c98f6e6f7b
2 files changed