Remove mode: "test" from android.security.flags-aconfig-java-host

Previously the config was correct in internal main but not updated in
aosp. Later the incorrect aosp config was applied to internal main and cause CtsAppSecurityHostTestCases fail. This CL fixes this problem.

Test: CI
Change-Id: Iaca74986ec16d8acb6b15b4d30908642fe0ccc9d