Export *CLASSPATH variables after apexes are configured.

For now, export the exact same values, on `post-fs-data` instead of on
`early-init` to soak the change. As a follow up, the actual values will
be generated by a new oneshot service.

See go/updatable-classpath for more details.

Bug: 180105615
Test: manual - device boots
Change-Id: I5f6826a0f87a5e01233e876d820e581feb555bca
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 863cf6c..9ac31d6 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -865,6 +865,10 @@
     wait_for_prop apexd.status activated
     perform_apex_config
 
+    # Export *CLASSPATH variables from /etc/classpath
+    # TODO(b/180105615): export from the generated file instead.
+    load_exports /etc/classpath
+
     # Special-case /data/media/obb per b/64566063
     mkdir /data/media 0770 media_rw media_rw encryption=None
     exec - media_rw media_rw -- /system/bin/chattr +F /data/media