Fix check on BOARD_SUPER_PARTITION_SIZE.

The original code doesn't use the size of images that
is calculated at build time, but instead use BOARD_*IMAGE_PARTITION_SIZE
variables. Update the logic to use the actual size of the images at
build time.

Test: builds with a device defining the value and
BOARD_SUPER_PARTITION_PARTITION_LIST := system vendor product productservices

Bug: 79106666
Change-Id: I07b3ee466482bd8f5cf709e13e16a7f187099aaf