Dialer: Fix possible crash in call details

* VOIP calling when multi-SIM is active can result in subscription being
  -1 at this point, resulting in array out of bounds when fetching the
  SIM icon.

Change-Id: I1ce2c3bb0b27b26b61967dfe90b38cc9740a1f54
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_Dialer into cm-11.0