Merge "Allow currysrc users to override srcgen and output directories" am: 0ed3bdf3d4

Original change: https://android-review.googlesource.com/c/platform/tools/currysrc/+/1555397

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ifbe7500c428f0f3a09a79c459ca5c338d209ddac