Add missing "Notify for every message"...

Since Email now uses UnifiedEmail, this setting defaults to false
and there is no way to enable it; this commit adds this option,
which is then honored by the unified notification engine.

Change-Id: I5d4464026c6532c9aac87016368cf8e13d9cfbb5
Merge "Add missing "Notify for every message"..." into cm-11.0