Add Virtual A/B with vendor ramdisk product.

If vendor_ramdisk exists, it is preferred to use launch_with_vendor_ramdisk.mk
because it moves e2fsck to vendor_ramdisk, making ramdisk smaller.

Devices that uses VABC is assumed to have a vendor ramdisk, so inherit
from this new makefile.

Test: pass
Change-Id: If6adad9985ca4750225fd4263edb42de1ddaf486

target/product/virtual_ab_ota/README.md

@@ -8,6 +8,8 @@ Devices that uses Virtual A/B must inherit from one of the makefiles in this dir
 launch.mk
   |- retrofit.mk
   |- plus_non_ab.mk
+
+launch_with_vendor_ramdisk.mk
   |- compression.mk
 
 compression_retrofit.mk

target/product/virtual_ab_ota/compression.mk

@@ -14,7 +14,7 @@
 # limitations under the License.
 #
 
-$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota/launch.mk)
+$(call inherit-product, $(SRC_TARGET_DIR)/product/virtual_ab_ota/launch_with_vendor_ramdisk.mk)
 
 PRODUCT_VENDOR_PROPERTIES += ro.virtual_ab.compression.enabled=true
 

target/product/virtual_ab_ota/launch_with_vendor_ramdisk.mk

@@ -0,0 +1,24 @@
+#
+# Copyright (C) 2020 The Android Open-Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Devices launching with Virtual A/B and has a vendor_boot partition is
+# preferred to inherit from this makefile instead of launch.mk.
+
+PRODUCT_VIRTUAL_AB_OTA := true
+
+PRODUCT_VENDOR_PROPERTIES += ro.virtual_ab.enabled=true
+
+PRODUCT_PACKAGES += e2fsck.vendor_ramdisk