Output dex_preopt to SDK snapshot.

This is needed to determine whether we need to deapex the profile or
not.

Bug: 241823638
Test: m nothing
Test: -
  1. Patch ag/20582608 PS2.
  2. TARGET_BUILD_APPS=com.android.wifi packages/modules/common/build/mainline_modules_sdks.sh
  3. See the `dex_preopt` property being written.
Change-Id: I05177388c24be1ab315247ea85e7e3a8600cebd3