early start zygote_secondary as well

- late start of zygote_secondary leads into occasional
  1 second wait for starting system service.
- Early start secondary zygote so that there is no additional
  wait.

bug: 37508384
Test: python packages/services/Car/tools/bootanalyze/bootanalyze.py -r -c packages/services/Car/tools/bootanalyze/config.yaml -n 100 -f -e 16 -w 30

(cherry picked from commit f8532445b4c2c693d6c4e8794a7d9a69da1e0a5f)

Change-Id: Ia46b07f3d6abb090cc169ebd807e21b16694d172
diff --git a/rootdir/init.rc b/rootdir/init.rc
index fd82513..4ebebb7 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -504,6 +504,7 @@
 on zygote-start && property:ro.crypto.state=encrypted && property:ro.crypto.type=file
    start netd
    start zygote
+   start zygote_secondary
 
 on boot
     # basic network init