ENH: propeller: use smoothSolver on transported quantities

tutorials/incompressible/pimpleDyMFoam/propeller/system/fvSolution

 /*--------------------------------*- C++ -*----------------------------------*\
 | =========                 |                                                 |
 | \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
-|  \\    /   O peration     | Version:  dev                                   |
+|  \\    /   O peration     | Version:  2.2.2                                 |
 |   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
 |    \\/     M anipulation  |                                                 |
 \*---------------------------------------------------------------------------*/
@@ -46,15 +46,15 @@ solvers
     "(U|k|epsilon)"
     {
         solver          smoothSolver;
-        smoother        GaussSeidel;
+        smoother        symGaussSeidel;
         tolerance       1e-6;
         relTol          0.1;
     }
 
     "(U|k|epsilon)Final"
     {
-        solver          PBiCG;
-        preconditioner  DILU;
+        solver          smoothSolver;
+        smoother        symGaussSeidel;
         tolerance       1e-6;
         relTol          0;
     }