Update Constants.java

changelog

Merge pull request qiniu#391 from sxci/v7.2.18

v7.2.18

Merge pull request qiniu#362 from sxci/add_bucket_private

 add bucketInfo, setBucketAcl, setIndexPage [ci skip]

Merge pull request qiniu#354 from liangchaoboy/master

add version

fix useless code

update changelog of v7.2.11

update changelog to publish v7.2.10

fix code style for static variables in Configuration

Merge pull request qiniu#308 from jemygraw/master

add new putpolicy parameter and update changelog