RemoveAppProperty returnvalue fix for invalid key

:Release Notes:
RemoveAppProperty returnvalue fix for for invalid key

:Detailed Notes:
Sqlite db returns true even if a delete query on an invalid key
is performed on DB. So, return value was always true even if
invalid key was passed.Patchset contains solution for returning
appropriate return value for invalid key.

:Testing Performed:
Compiled locally and tested on official starfish build.

:Issues Addressed:
[GF-54054] RemoveAppProperty is returning true for invalid parameters

Open-webOS-DCO-1.0-Signed-off-by: Ashish Sadre <ashish.sadre@lge.com>

Change-Id: Iefcd77afdde5d487c4534f7475645747901e5063
Reviewed-on: https://g2g.palm.com/4199
Reviewed-by: DCO Verification
Reviewed-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Tested-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>