Revert "Boot image extension."

This reverts commit 4f6ebe89af462ff05d97433deb2bca3f3b011fc2.

Reason for revert: b/143492855

Bug: 119800099
Bug: 143492855
Change-Id: I27da7e790f61f836701f8f39c98d14b507af8b9e
9 files changed