Allow on device spl downgrade check to be bypassed am: 85a6d997f5 am: 238e35116c

Original change: https://android-review.googlesource.com/c/platform/system/update_engine/+/2800054

Change-Id: I8137042f8a5b99ca1a15047e4c1991718cb53ba7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>