Themes: Map themed icon to app after upgrade

Before this patch, applying an icon theme and then upgrading an app would
cause the app to lose its themed icon.

Change-Id: Ia76a33d0fb731720aa735e9dd9596bc5d2e75d9f
Merge "Themes: Map themed icon to app after upgrade" into cm-11.0
Merge remote-tracking branch 'cm/cm-11.0' into cm-11.0