Merge "Use Python 3 in Mesa build scripts." am: fba4d6a23e am: bc614be055

Original change: https://android-review.googlesource.com/c/platform/external/mesa3d/+/2320671

Change-Id: Ifb5959df918c087fdd91484b3e18fb74917ef809
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>