Bumping AOSP Contacts version to 1.4.15 am: d2ac793647  -s ours
am: 0b69d7cdf4

* commit '0b69d7cdf4232b4ff7d52ac858e823aa72cdac28':
  Bumping AOSP Contacts version to 1.4.15

Change-Id: If60a142502122e328f519d228e7d2ddced352c69