Fix casting warnings in ContactSaveService

packages/apps/Contacts/src/com/android/contacts/ContactSaveService.java:1227: warning: non-varargs call of varargs method with inexact argument type for last parameter;
                    R.string.contacts_deleted_many_named_toast, names);
                                                                ^
  cast to Object for a varargs call
  cast to Object[] for a non-varargs call and to suppress this warning
1 warning

Test: make -j Contacts (no more warnings)
Change-Id: I244f376b2a8728598e66757742234fbf1a3557df