Fix the bad merge of conditionally packaging VBOOT_SIGNER tools CL.

Commit d2aed430 didn't get merged
correctly when flowing from AOSP into internal. It only added the new
lines but without deleting the old lines (due to an inconsistent revert
in internal branch).

Bug: 35467608
Test: lunch bullhead-userdebug; m otatools-package; verify the generated
      otatools.zip doesn't include VBOOT_SIGNER stuff.
Change-Id: I49064bb7beb1215543037cf94712d03b0c2537b2