After de-extension-alization of Presentation Minimizer, it is important that its
UNO implementation names are different from the ones used by the extension (in
case the extension ever is installed as shared or per-user).  For
com.sun.star.comp.PPPOptimizer it appears to be easiest to not advertise this as
a service at all, but rather instantiate the object directly where used.  (For
com.sun.star.comp.PresentationMinimizerImp the necessary renaming had been done
in the previous commit already.)

Change-Id: I954b715f2d434cecf9abd2776b39c4ed3152c5ec