goldfish: get a default gralloc

Right now, the default gralloc is at hardware/libhardware
and it is used by emulator and other vendors (maybe during
some hardware bringup)

Having our own gralloc for -gpu guest will make working on
-gpu guest bugs faster (we own goldfish project) and safer
(as it only impacts emulator)

note: the number of framebuffer is changed from 2 to 1

Change-Id: Ic4620fb579769793b406d87a364548a5af5aa45a
Merged-In: Ic4620fb579769793b406d87a364548a5af5aa45a
6 files changed