dynamic_partitions_info.txt: use dump-dynamic-partitions-info

Use the same procedure to avoid code duplication.
Note that dump-dynamic-partitions-info not only has more information,
but also changes keys:
- from X_size to super_X_group_size
- from X_partition_list to super_X_partition_list

delta_generator is updated to recognize these new keys as well.

Test: build ota package
Test: forrest
Change-Id: I6a973fc113fb80b352822a14991cad027c72cf06