Activate apexes in /system_ext/apex, /vendor/apex

As VNDKs can be installed /system_ext/apex or /vendor/apex,
otapreopt_chroot activates apexes in those directories as well.

Bug: 137802149
Bug: 140136207
Test: m otapreopt_chroot
Change-Id: I11e3310d83a53759339ae5e86c19c49736a5f71d