fastboot: Add vendor_kernel_boot

Bug: 234474672
Bug: 214409109
Signed-off-by: Lucas Wei <lucaswei@google.com>
Merged-In: I8b0baa887e5e2309a1cb4a602fe8f6ca9e22526b
Change-Id: I60b7ec0c160d38e01b15ed547d51a2a007bfd7f5
2 files changed