Readd snapd to the seed.

With LP: #1730159 now resolved, snapd will not run by default on Lubuntu and
take no memory; so it's time to drop this delta from the default Ubuntu
experience.

blacklist

@@ -6,8 +6,3 @@
 network-manager-config-connectivity
 network-manager-config-connectivity-ubuntu
 network-manager-config-connectivity-debian
-
-# snapd automatically uses a bit of RAM, and Lubuntu doesn't plan on ever installing
-# Snaps by default, so let's not even put it on the ISO, people can install it if they
-# want it...
-snapd

supported

@@ -40,7 +40,6 @@ included due to matching Extra-Include patterns, and has no other effect):
  * Extra-Exclude: libgl1-mesa-dri-experimental-dbg # LP: #638097
  * Extra-Exclude: python-vigra-doc # libvigraimpex is in main, but nothing uses python-vigra
  * Extra-Exclude: libunity-*-dev unity-2d-dbg
- * Extra-Exclude: snapd
 
 
 Transitional packages: