Changes

[3/7] personalization: refactor Puk

Implement abstract DecimalHexParam, and use it to refactor Puk1 and Puk2
to the new ConfigurableParameter implementation style.

DecimalHexParam will also be used for Pin and Adm soon.

Change-Id: I271e6c030c890778ab7af9ab3bc7997e22018f6a