It's impractical to use snapshots in your job when you're using the android-emulator plugin, as it has two modes of operating:
a) android-emulator manages and loads a snapshot,
b) android-emulator disables snapshot support.

While it would be possible for the job itself to use snapshots in a (simply by using a different snapshot name), having more than a single snapshot in a snapshot.img is currently broken (as reported in http://code.google.com/p/android/issues/detail?id=15922 - though no update so far).
This only leaves the possibility of disabling snapshots in android-emulator, but when you choose not to use snapshots it passes the -no-snapstorage, making snapshots unusable for any jobs running. Why was this design decision made - is there some gain to be had?

I've attached a simple patch that simply disables this behavior in b, until android issue 15922 is resolved.