Add user for credstore.

The credstore system daemon is running as an unprivileged user. This
CL adds this user and also creates a directory (/data/misc/credstore/)
where this daemon can store its data.

Bug: 111446262
Test: N/A
Change-Id: I8da2c32dd04fef797870b8a7bbc5e499bed71f9e
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 00053ad..0d6c189 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -551,6 +551,7 @@
     chown bluetooth bluetooth /data/misc/bluedroid/bt_config.conf
     mkdir /data/misc/bluetooth 0770 bluetooth bluetooth
     mkdir /data/misc/bluetooth/logs 0770 bluetooth bluetooth
+    mkdir /data/misc/credstore 0700 credstore credstore
     mkdir /data/misc/keystore 0700 keystore keystore
     mkdir /data/misc/gatekeeper 0700 system system
     mkdir /data/misc/keychain 0771 system system