Don't add Jack dependencies when building without Jack

Runtests add dependencies on the core library classes.jack files,
which don't exist when compiling with javac.  Disable the dependencies
when building without Jack for now.

Test: m -j ANDROID_COMPILE_WITH_JACK=false tests
Change-Id: I40925c8c8536cc048e7308e6202db420154a18aa
1 file changed