Label dtbo_block_device with flag-guarding am: 0c15160cad

Original change: https://android-review.googlesource.com/c/device/google/zuma-sepolicy/+/2903809

Change-Id: I0f245e7f165401304b99d07ef7c064d9d86f0a74
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>