Spooler broken on upgrade.

The spooler apk was signed with the platform certificate and used
a redundant shared user id. Now the spooler is signed with a default
certificate and uses the same share user id. Since the shared user
id is associated with the platform certificate the package manager
rejects the spooler apk because it requested the same shared user id
with a different certificate. This change removes the unnecessary
shared user id from the manifest.

Change-Id: I208ef17fc6c25e67338682e56f9ce0e7e9d65642