Move postgres to list of supported images
Move postgres to list of supported images

PiperOrigin-RevId: 197104043
Change-Id: I377c0727ebf0c44361ed221e1b197787825bfb7b

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor