Merge remote-tracking branch 'aosp/pie-gsi' into HEAD

* aosp/pie-gsi:
  Allow GSI targets to build otatools.zip
  Prevent AVB signing from using _RESERVED_SIZE
  releasetools: Clean up the use of `partition_size`.
  releasetools: Fix an issue in image size computation.
  releasetools: Return the actual image size when building logical partitions.
  DO NOT MERGE ANYWHERE: Split PRODUCT_USE_LOGICAL_PARTITIONS into sub-flags.
  DO NOT MERGE ANYWHERE: Revert "Split PRODUCT_USE_LOGICAL_PARTITIONS into sub-flags."
  Enable AVB signing on GSI
  Adding better AVB error message
  Remove the hack that uses INSTALLED_RAMDISK_TARGET as INSTALLED_BOOTIMAGE_TARGET.

Change-Id: Ieed7dd572e305b0593f5ccbae1f3088d1f40278c