Revert "Label dtbo partition as dtbo_block_device" am: f05143f43c

Original change: https://android-review.googlesource.com/c/device/google/zuma-sepolicy/+/2903808

Change-Id: If197a913485f18554bf650c37c85911afa00a804
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>