Fix and cleanup.

- Detect java-source-list before transforming to java-source-list-uniq.
  This fixes non-fatal errors in build log like:
  /bin/bash:
  out/target/common/obj/APPS/android.core.tests.libcore.package.tzdata_intermediates/classes/java-source-list:
  No such file or directory
- Cleaned the outdated incrementaljavac. Nobody is using this feature
  and now we switched to jack.

Change-Id: If1adb9b5820d9b295a11984c0f170f9a7ff4de7b