scripts: Import lineage aosp-merger script

* From https://github.com/LineageOS/scripts/blob/f07e1584f76000039554477cef405c4096d23e73/aosp-merger/aosp-merger.sh

Change-Id: Ia289f8dc83a82ef252793bb6b2f757afb2bf45c3
1 file changed
tree: a7cac40b131d4185ff0cf791c9cdfcf5701f9af1
  1. aosp-merger/