Fix a typo in estimated sizing per metric under archive policies
Fix a typo in estimated sizing per metric under archive policies

Change-Id: Ib86f7247ba2ff27336ef4529e64fd86503690304

leandroreox/gnocchi,gnocchixyz/gnocchi,gnocchixyz/gnocchi,leandroreox/gnocchi,sileht/gnocchi,sileht/gnocchi