chown only to the folder to store the config.json (#4984)

Narrow down the scope of `chown` in adminserver because the
/etc/adminserver/config/ is the location to store the config.json file.
And /etc/adminserver/key should be readonly.

make/photon/adminserver/start.sh

 #!/bin/sh
-if [ -d /etc/adminserver ]; then
-    chown -R 10000:10000 /etc/adminserver
+
+#In the case when the config store is set to filesystem, the directory has to be writable.
+if [ -d /etc/adminserver/config ]; then
+    chown -R 10000:10000 /etc/adminserver/config
 fi
 sudo -E -u \#10000 "/harbor/harbor_adminserver"