Merge "Export related make variables for gralloc.default to soong" into main am: b3984cac

Original change: https://android-review.googlesource.com/c/platform/build/+/3211281



Change-Id: I2488d9021d4917065f14405e70bb98a141824b61
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>