minigbm: Android.bp: Add virgl varient of gralloc.minigbm am: 7658cd6a0e am: d0d2cf377a

Original change: https://android-review.googlesource.com/c/platform/external/minigbm/+/1881150

Change-Id: I7fc2ee4d2298cdf37ba507981c398e43087ba2d7