Enable contact photo preloading.

Avoids the delay occuring otherwise when checking into call details.

Change-Id: Ie48285bb03fde0434429079f141ec57dc75a65b9
Merge "Enable contact photo preloading." into cm-10.2
Merge branch 'cm-10.2' of https://github.com/CyanogenMod/android_packages_apps_Dialer into cm-10.2