Merge changes from topic "from-pi-gsi" into pie-gsi

* changes:
  Enable dynamic image size on aosp_arm_64b_ab
  Add aosp_arm_64b_ab product
  Fix unbundled branch by not having it pick up goldfish dependency
  Add emulator audio policy config in /vendor not /system
  emulator: factor vendor partition out of emulator.mk
  Enable dyanmic image size for GSI
  Split PRODUCT_USE_LOGICAL_PARTITIONS into sub-flags.
  Remove vr_hwc from GSI image.
  ro.boot.logical_partitions moved to product image
  Build image for super partition
  Add PRODUCT_OTA_ENFORCE_VINTF_KERNEL_REQUIREMENTS.
  Build GSIs (aosp_$arch products) in sparse format
  Add more ro.vendor.build.*
  Fix check on BOARD_SUPER_PARTITION_SIZE.
  build_image.py recognize BOARD_PRODUCTIMAGE_PARTITION_RESERVED_SIZE
  releasetools: Rename the ramdisk_dir in prop dict to root_dir.
  Add A/B update to GSI
  Move some BoardConfig settings from EmuCommon to GsiCommon
  Create extra symbolic links at root for arm64 GSI
  Add USE_XML_AUDIO_POLICY_CONF to GSI
  Refactor BoardConfig.mk for emulator products
  Add BOARD_SUPER_PARTITION_*
  build_image.py recognize BOARD_VENDORIMAGE_PARTITION_RESERVED_SIZE
  build_image.py recognize BOARD_SYSTEMIMAGE_PARTITION_RESERVED_SIZE
  androidboot.lrap => logical_partitions
  generate-image-prop-dictionary only generates relevant variables
  Add ro.boot.logical_partitions
  Remove unnecessary branch for BOARD_HAS_EXT4_RESERVED_BLOCKS.
  Add PRODUCT_USE_LOGICAL_PARTITIONS