I use example from TappyChicken project and it works well.
Here is PakBlacklist-Shipping.txt sample:
../../../Engine/Content/EditorMeshes/ColorCalibrator/
../../../Engine/Content/EngineDebugMaterials/
../../../Engine/Plugins/Runtime/LeapMotionController/
../../../TappyChicken/AssetRegistry.bin
Full path must be [Project]/Build/Android/PakBlacklist-Shipping.txt.
May be you use incorrect file name case (PakBlackList-Shipping.txt instead of PakBlacklist-Shipping.txt).