Add models to String.intern test

This will become necessary when the String.intern implementation is
moved to models.

Author: romainbrenguier

jbmc/regression/strings-smoke-tests/java_intern/test.desc

@@ -1,6 +1,6 @@
 CORE
 test_intern.class
---max-nondet-string-length 1000 --function test_intern.main
+--max-nondet-string-length 1000 --function test_intern.main --cp `../../../../scripts/format_classpath.sh . ../../../lib/java-models-library/target/core-models.jar` --unwind 10
 ^EXIT=0$
 ^SIGNAL=0$
 ^\[.*assertion.1\].* line 9.* SUCCESS$