Change default size of ODM partitions to be 512 MiB each.

For boards with 4 GiB eMMC, the default partitioning setup only leaves
around ~500 MiB of space for the userdata partition. Change the size of
the ODM partitions from 1024 MiB to 512 MiB each - this will leave an
additional 1024 MiB for use in the userdata partition.

TEST=Built an image and partitions have expected size.

Change-Id: I351dd6a3cb73ac320cb81580d305e1882efe8128
1 file changed