Finally fix the SolverBasedTest unit tests.
Creating FormulaManagerView does not work with the default configuration
for all of the solvers, so we should do it only in the subclasses
that actually require such an instance.

git-svn-id: https://svn.sosy-lab.org/software/cpachecker/trunk@14639 4712c6d2-40bb-43ae-aa4b-fec3f1bdfe4c