Skip class path checking for secondary dex files

Pass '&' marker to dex2oat classpath when compiling secondary dex files.
This will skip class path checking when loading the oat files.

Test: adb shell cmd package compile -m speed -f --secondary-dex com.google.android.gms
      oatdump --header-only --oat-
file=/data/user/0/com.google.android.gms/app_chimera/m/00000006/oat/arm64/DynamiteModulesC_GmsCore_prodmnc_alldpi_release
      check that the class path contains the special '&' marker

Bug: 32871170
Change-Id: If0628aeb4e3f5717604bfc4a87a4b1d438e5fa65