Merge "Don't use a secdiscardable file for keys encrypted by SP" am: 7cc31eb7b0 am: da999d55e5

Original change: https://android-review.googlesource.com/c/platform/system/vold/+/2242561

Change-Id: Id33248ab1c5f46ae350dd73a826bb4797f0584c4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>