Don't disable dexpreopt for an unbundled build.

Dexpreopt generates profiles that need to be installed in the APEX.
Soong will skip the dex2oat step after it generates the build rule for
profiles.

Bug: 241823638
Test: -
  1. Patch ag/20581649 PS2.
  2. banchan com.android.btservices x86_64 && m
  3. Check that "javalib/service-bluetooth.jar.prof" exists in the APEX.
Change-Id: I5cad1b0e1027935fd78e80ad7b07e039f7b8d432