Allow `otapreopt` to use bind-mounted Bionic artifacts from the Runtime APEX.

Allow `otapreopt_chroot` to:
- bind-mount Bionic artifacts from the Runtime APEX
  (`/postinstall/apex/com.android.runtime`) into `/postinstall/bionic/`;
- read the `/postinstall/system/bin/linker(64)` symlink to
  `/postinstall/bionic/bin/linker(64)` when executing
  `/postinstall/system/bin/otapreopt`.

Allow `otapreopt` (running as `postinstall_dexopt`) to:
- read directories under `/postinstall`.

Test: m otapreopt_chroot
Test: A/B OTA update test (asit/dexoptota/self_full).
Bug: 113373927
Bug: 120266448
Change-Id: I6de9df12d5fd84f1dd92798efed5f2d8b72d3ebe
2 files changed