Add a new command "--security" to boot commands. If this command is
observed as part of BCB, choose a different background text picture
for installing stage in recovery UI. As a result, users will see
"installing security update" instead of "installing system update"
when applying a security update package.
Bug: 27837319
Change-Id: I2e2253a124993ecc24804fa1ee0b918ac96837c5
This changes the verification code in bootable/recovery to use
BoringSSL instead of mincrypt.
Cherry-pick of 452df6d99c, with
merge conflict resolution, extra logging in verifier.cpp, and
an increase in the hash chunk size from 4KiB to 1MiB.
Bug: http://b/28135231
Change-Id: I1ed7efd52223dd6f6a4629cad187cbc383d5aa84
