This declares that the Email app might be using cleartext network
traffic (e.g., HTTP instead of HTTPS). This CL does not change the
behavior of the app. The flag added by this CL to the app's manifest
will make it easier to identify apps that use cleartext traffic in
the future.
Bug: 19215516
Change-Id: Ia55589151a77eb175149aaaf4f7cb4975ecb9c69