Small validation fix

No one ever calls the setStreamWithCrops API with a map of several
elements with one of the key being ORIENTATION_UNKNOWN: UNKNOWN is only
used internally.

But if it happens, it could lead to undefined behaviours

Flag: EXEMPT bugfix
Bug: 380271538
Test: presubmit
Change-Id: I69aca9ecf031485bcbfc4b149c6c426aa306797d