Return valid value when falling back to openDemux am: 7633bf9e am:...

Return valid value when falling back to openDemux am: 7633bf9e am: 9ab8a3d3 am: a83721ed am: b0f67d99

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/23149633



Change-Id: I7bec8860e0fa320a7e24370d4edaa4b62b5b92fd
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>