Add missing AB partitions to img.zip

Add all AB partitions to img.zip, so that we can verify integrity of a
build by running avbtool on img.zip .

Bug: 274923679
Test: img_from_target_files on a pixel build. Unzip the generated img
zip, run avbtool verify_image --follow_chain_partitions --image
vbmeta.img, make sure result is successful.

Change-Id: I7d586a6f2ad87d8ebf87b788947055339b1121a2