Merge "Move the creation of the root structure to build/core/main.mk" into main am: 963298af97

Original change: https://android-review.googlesource.com/c/platform/build/+/3261773

Change-Id: Ia48ed90bf14c89f1e8209cf8ec29f2349adf8886
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>