Remove the disable_cdex P/H flag.

Compact dex is now always rejected.

Test: banchan com.android.art && m
      adb install out/dist/com.android.art.apex
      adb reboot
      adb shell pm bg-dexopt-job
      adb shell "find data/app data/dalvik-cache -name \*.vdex \
                 | sort | xargs ls -l" > before
      adb shell pm bg-dexopt-job
      adb shell "find data/app data/dalvik-cache -name \*.vdex \
                 | sort | xargs ls -l" > after
      diff before after -> check that vdex files haven't changed
Bug: 256664509
Change-Id: If65c06b110100665320c42ef55572d33201b77a0