Revert "Have `otapreopt_chroot` mount APEX packages in the chroot dir."

This reverts commit 833e6364.

Reason for revert: Breaks com.google.android.tradefed.dexoptota.PreRebootTest.

Change-Id: I98d75933c711657d707f3239f91939d11e202fdd
Test: m otapreopt_chroot
Test: A/B OTA update test (asit/dexoptota/self_full).
Bug: 113373927
Bug: 120796514