ASACORE-1006 About Feature - Check for required AboutData fields

When AboutObject.Announce is called the value returned by the
AboutDataListener is checked to make sure all of the required fields
are populated. If a required field is missing then the status
ER_ABOUT_ABOUTDATA_MISSING_REQUIRED_FIELD is returned.

Change-Id: I59b9bf8a361150366a9e7ac97b86fbe786c49a89
Signed-off-by: George Nash <georgen@qce.qualcomm.com>