Revert "Allow init boot_block_device:lnk_file relabelto." Revert submission 1514903-chain_vbmeta_redbull Reason for revert: test b/174826519 Reverted Changes: I1cae1ef76:Enable chained vbmeta for boot I820cbaf20:Allow init boot_block_device:lnk_file relabelto. Change-Id: Id51daf34350031d7cbe3722484c8b14ebfcaeec2 (cherry picked from commit 5e56a1384029c486f8e4560a5559efbe1bc98480)