Revert "Exec_start derive_classpath on post-fs-data."

Revert "Introduce derive_classpath service."

Revert "Introduce derive_classpath."

Revert submission 1602413-derive_classpath

Bug: 180105615
Fix: 183079517
Reason for revert: SELinux failure leading to *CLASSPATH variables not being set in all builds

Reverted Changes:
I6e3c64e7a:Introduce derive_classpath service.
I60c539a8f:Exec_start derive_classpath on post-fs-data.
I4150de69f:Introduce derive_classpath.

Change-Id: Iefbe057ba45091a1675326e3d5db3f39cc3e2820
diff --git a/rootdir/init.rc b/rootdir/init.rc
index d1e6ee2..0e1e98b 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -881,12 +881,9 @@
     wait_for_prop apexd.status activated
     perform_apex_config
 
-    # Define and export *CLASSPATH variables
-    mkdir /data/system/environ 0700 system system
-    # Must start before 'odsign', as odsign depends on *CLASSPATH variables
-    exec_start derive_classpath
-    load_exports /data/system/environ/classpath
-    rm /data/system/environ/classpath
+    # 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
@@ -902,7 +899,6 @@
 
     # Start the on-device signing daemon, and wait for it to finish, to ensure
     # ART artifacts are generated if needed.
-    # Must start after 'derive_classpath' to have *CLASSPATH variables set.
     exec_start odsign
 
     # After apexes are mounted, tell keymaster early boot has ended, so it will