Delete BootPrebuilt.

They are unused.

Test: TH
Change-Id: I57c93ba93226b3694eba187a8531fbe00036d918
(cherry picked from commit 817cb975f4009c88bed6e984b78d8972d461650e)
Merged-In: I57c93ba93226b3694eba187a8531fbe00036d918
1 file changed
tree: 4b825dc642cb6eb9a060e54bf8d69288fbee4904

This tree is empty.