Change Stemcell Builder to always create vcap user with uid 1000
Change Stemcell Builder to always create vcap user with uid 1000

[#104747022](https://www.pivotaltracker.com/story/show/104747022)

Signed-off-by: Thinh Nguyen <381db031081d050934f1b36fa4ab3bf1b5383408@emc.com>

barthy1/bosh,barthy1/bosh,barthy1/bosh,barthy1/bosh