ThemerConstants: Replace nulls with empty strings
ThemerConstants: Replace nulls with empty strings

The anti-piracy library prefers empty strings to denote
that you don't want the features enabled rather than
null. Thanks a ton to Davey for testing this one :)

Reported-and-tested-by: David Wilson <c2dd4ba7631c1da2911849a0d51ec48b7d42f046@hotmail.com>
Signed-off-by: Harsh Shandilya <25a9fc4361f0de99d66f569f23dc0154e7064e35@prjkt.io>

Citrus-CAF/packages_apps_Margarita,Citrus-CAF/packages_apps_Margarita,Citrus-CAF/packages_apps_Margarita