[assembly] Replace empty-minfs with empty-data

New products may use different data filesystems (e.g. fxfs) which are
formatted on first boot if the data partition is empty. Replace uses of
minfs with filesystem-agnostic data identifier.

Bug: 85134
Change-Id: I4b593af1222c9b5e7d89e45227f90a15b7590eff
Reviewed-on: https://fuchsia-review.googlesource.com/c/sdk-integration/+/789223
Reviewed-by: Jiaming Li <lijiaming@google.com>
Commit-Queue: Brandon Castellano <bcastell@google.com>