Ceph-RGW: fix file permision issue

This is to fix the issue we are facing with file permision on the file
/var/lib/ceph/bootstrap-rgw/ceph.keyring since owner of the file
will be root.

This is happening when node with rgw reboots and rgw pods fails at
init after reboot,this is happening on sinlge node deplyoments.

issue:

ceph-rgw-5db485fbd9-dv778  0/1  Init:CrashLoopBackOff   5  6m49s

logs:
+ chown -R ceph. /run/ceph/ /var/lib/ceph/bootstrap-rgw /var/lib/ceph/radosgw
/var/lib/ceph/tmp
chown: changing ownership of
'/var/lib/ceph/bootstrap-rgw/ceph.keyring': Operation not permitted

Change-Id: Idcb648c205053b2f03357b59173e70e02f28688c

ceph-rgw/templates/bin/_init-dirs.sh.tpl

@@ -37,5 +37,8 @@ mkdir -p /run/ceph
 # Creating rados directories
 mkdir -p "/var/lib/ceph/radosgw/${RGW_NAME}"
 
+# Clean the folder
+rm -f "$(dirname "${RGW_BOOTSTRAP_KEYRING}"/*)"
+
 # Adjust the owner of all those directories
 chown -R ceph. /run/ceph/ /var/lib/ceph/*