Restrict the symbols exported by libandroid_runtime on host

This explicitly defines which symbols should be exported by
libandroid_runtime on host. This is to avoid potential collisions with
other libraries loaded on a host system.
This also fixes the dist path of the builds.

Flag: NONE host-only change
Bug: 382086021
Test: m libandroid_runtime on host
Change-Id: I3f8c160f0920b56becfe7bf79af7638d534ca200