Do not pass --runtime-arg -classpath to dex2oat in dex fuzz

There is no need for it. It only adds the dex file to be compiled and that
provides no useful information to dex2oat.

Bug: 38138251
Test: build and run the fuzzer

(cherry picked from commit 46555f8c4a3a430cd5cfc8854c39bb565a72782b)

Change-Id: I83c17df2fb295efe9f38c39376c070840c369964
1 file changed