Bug 876746 - Gaia changes for MMS Delivery report support

Patch for MMS delivery report handling. Changes in both settings / message spp:
- Settings : Add manual control for delivery report because there is only one delivery report option on UI for controlling 2 settings key(sms/mms).
- Message: deliveryStatus for mms message is an array, so we nee to handle both sms(string) and mms(array) properly. In multiple recipients case, doulbecheck icon will show up only when all the success event is received.