Fix dex signatures of methods with varargs

Doclava implicitly adds an extra dimension to the last parameter
of vararg methods. Generation of dex signatures assumed this was
not the case. Fix the problem.

Bug: 64382372
Test: inspect private-dex.txt, search for:
      Ljava/lang/invoke/VarHandle;->get->
          ([Ljava/lang/Object;)Ljava/lang/Object;
Change-Id: I99311b4603d2992e4c9f8b19b6d60cea3b42bed3
1 file changed