Merge "Allow currysrc users to override srcgen and output directories" am: 0ed3bdf3d4 am: e7290b44c9 am: c39f198ad4

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

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ie5899998471ff5c1fa36a1a5c05e7ffd77a91f1c