Revert "Remove redundant null_blk and scsi_debug vendor kernel modules"

This reverts commit 78f839e5bc1e2b96f13557b33ca3eadfa6b56ca8.

Reason for revert: original CL has been reverted in aosp/2982953

Change-Id: Icaa8c3a31f53ad0b22aa9884e7ca7042b8c8c18f
1 file changed