MAP: Synchronize mMsgList to avoid extra MessageDeleted MNS event

Precondition:
There are no messages in Messaging App.

Use Case:
1. Connect to MSE on Mas insance 0,
   Register and Enable Event Notifications from any MCE.
2. Set Path to root.
3. Set Path to telecom.
4. Set Path to msg.
5. Set Path to outbox.
6. Compose an SMS and add the recipient.
7. Click PushMessage option.

Failure:
Map Server sends a unexpected MessageDeleted EventReport Notification
even though PushMessage received from MCE is processed Successfully.

Root Cause:
Issue happens only for one corner case, where onChange() gets triggered
while processing a local initiated pushMsg before the entry is appended
to database, as local MsgListSms contains an extra entry for newly added
msg from MCE.

Fix:
Synchronize contentObserver mMsgList SMS/MMS to update list with
local initiated changes before fetching complete database list and
handling onChange() to avoid extra MessageDeleted MNS event.

Change-Id: Id4d5dad4d2b4b1e17f40218c11d13e39c9b885a0