Move write-partition-file-list out of if statement

write-partition-file-list was mistakenly moved into an
`ifdef BUILDING_RAMDISK_IMAGE`, so it caused other partitions to fail
to build on products that don't use a ramdisk.

Bug: 378738827
Test: Will run abtd on the failing product
Change-Id: I270adbed74054b573e5dab40e5900ceca45e1dfc