Add new "pin complex" type to supported keyguard PINs

This adds a feature to allow DevicePolicyAdmins to prevent using
simple PINs, which are defined as those containing more than 3
repeated values. Examples include '1234', '2468', '1111', '9876', etc.

Bug 12081139

Change-Id: I68d8fe2459837cb5e083724e1740e65f0519f7e1