minigbm: Android.bp: Add virgl varient of gralloc.minigbm am: 7658cd6a0e am: d0d2cf377a am: 70a57f9ab2

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

Change-Id: I94d3e44345a215ecc54f080b5e3ca4e2c696b9e1