Rename a couple of methods related to redefinition for readability

TransformClasses is a method to actually redefine the method and
TransformClassesDirect is a method to call ClassFileLoadHooks which is
confusing. So rename TransformClassesDirect to CallClassFileLoadHooks
and also add some comments

Also rename GetRedefinitionError to CanRedefineClass.

Test: art/test.py
Change-Id: Ie04927f1aae2880d87bcb9bb19b5f3971911fd43
5 files changed