Add devices suitable for single-arch module builds

Prior to this the generic_* devices were typically used for this
purpose. There are a few reasons to create new specific ones:
- the generic_arm64 device has a hack specifically for building
  multi-arch packages that we want to avoid
- the generic_* devices include a bunch of emulator config that does not
  make sense for unbundled builds

Bug: 172256440
Test: verify unbundled builds migrated from generic_* don't change
Change-Id: Ia937461aa24a5d5b542f8688a1b71ac3fdeb596b