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

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

Change-Id: Ieb83e8fb1ab24f51c0fba7a3527ed25cb8ebc30e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>