Merge "GSI vbmeta.img: set rollback_index to zero"

# Android Verified Boot (AVB):

#   Set AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED (--flags 2) in

#   vbmeta.img to disable AVB verification.

#   vbmeta.img to disable AVB verification. Also set the rollback index

#   to zero, to prevent the device bootloader from updating the last seen

#   rollback index in the tamper-evident storage.

#

# To disable AVB for GSI, use the vbmeta.img and the GSI together.

# To enable AVB for GSI, include the GSI public key into the device-specific

# vbmeta.img.

BOARD_AVB_ROLLBACK_INDEX := 0

BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --flags 2

# Enable chain partition for system.