Missing back button on MultiSimSettings ActionBar

Fixed missing back button on ActionBar (default Settings behavior on
submenus) by adding "parentActivityName" property to MultiSimSettings
activity.

Change-Id: I60a1123be29d81c8232e0acee1ac9544bf9b32e6
Merge "Missing back button on MultiSimSettings ActionBar" into cm-11.0
Merge pull request #2 from CyanogenMod/cm-11.0

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