Revert "Revert "Enable chained vbmeta for boot""

This reverts commit 8ed24f1c7f8923e0b0ac62c16abc5ea32c1a11e0 which
disables chained vbmeta for boot.

Bug: 176930600
Test: manually verify chained vbmeta is enforced
Change-Id: Iba79a072798ff4dd0eb9add3c36d7f6c1ffb4655
diff --git a/BoardConfig-common.mk b/BoardConfig-common.mk
index 888761d..6fc4244 100644
--- a/BoardConfig-common.mk
+++ b/BoardConfig-common.mk
@@ -144,6 +144,12 @@
 BOARD_AVB_VBMETA_SYSTEM_ROLLBACK_INDEX := $(PLATFORM_SECURITY_PATCH_TIMESTAMP)
 BOARD_AVB_VBMETA_SYSTEM_ROLLBACK_INDEX_LOCATION := 1
 
+# Enable chained vbmeta for boot images
+BOARD_AVB_BOOT_KEY_PATH := external/avb/test/data/testkey_rsa2048.pem
+BOARD_AVB_BOOT_ALGORITHM := SHA256_RSA2048
+BOARD_AVB_BOOT_ROLLBACK_INDEX := $(PLATFORM_SECURITY_PATCH_TIMESTAMP)
+BOARD_AVB_BOOT_ROLLBACK_INDEX_LOCATION := 2
+
 TARGET_USERIMAGES_USE_EXT4 := true
 TARGET_USERIMAGES_USE_F2FS := true
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 11796480000
diff --git a/conf/fstab.gs101 b/conf/fstab.gs101
index f002b03..d649b1b 100644
--- a/conf/fstab.gs101
+++ b/conf/fstab.gs101
@@ -8,6 +8,7 @@
 system_ext                                               /system_ext                 ext4    ro,barrier=1             wait,slotselect,avb=vbmeta_system,logical,first_stage_mount
 product                                                  /product                    ext4    ro,barrier=1             wait,slotselect,avb=vbmeta_system,logical,first_stage_mount
 vendor                                                   /vendor                     ext4    ro,barrier=1             wait,slotselect,avb=vbmeta,logical,first_stage_mount
+/dev/block/platform/14700000.ufs/by-name/boot            /boot                       emmc    defaults                 slotselect,avb=boot,first_stage_mount
 /dev/block/platform/14700000.ufs/by-name/efs             /mnt/vendor/efs             ext4    defaults,noatime,rw      wait,check,formattable
 /dev/block/platform/14700000.ufs/by-name/efs_backup      /mnt/vendor/efs_backup      ext4    defaults,noatime,rw      wait,check,formattable
 /dev/block/platform/14700000.ufs/by-name/modem_userdata  /mnt/vendor/modem_userdata  ext4    defaults,noatime,rw      wait,check,formattable