Cherry pick of commit 49d8d5b41a344dc523648a0162ff4d7b2e095b4b

Signed-off-by: Glenn Oppegard <goppegard@pivotallabs.com>
upgrade stemcell rsyslog to 7.4.6 and include RELP support

[#57322202]

Signed-off-by: Glenn Oppegard <goppegard@pivotallabs.com>