Skip ab/6749736 in stage.

Merged-In: I786a11712dd0f5139b8b69bff36c916a7a80b29f
Change-Id: Idfbb8fbab29383691ab4ba1d34d1129d50c9000c
tree: 703130dd9b051b0f64dd23f4d9c9e2d2a01e70c0
  1. hikey/
  2. hikey960/
  3. update-prebuilts.sh