[Java] Update HdrHistogram to 2.1.8
[Java] Update HdrHistogram to 2.1.8

oleksiyp/Aeron,mikeb01/Aeron,EvilMcJerkface/Aeron,galderz/Aeron,mikeb01/Aeron,tbrooks8/Aeron,EvilMcJerkface/Aeron,EvilMcJerkface/Aeron,gkamal/Aeron,oleksiyp/Aeron,gkamal/Aeron,EvilMcJerkface/Aeron,oleksiyp/Aeron,real-logic/Aeron,galderz/Aeron,real-logic/Aeron,real-logic/Aeron,mikeb01/Aeron,tbrooks8/Aeron,real-logic/Aeron,tbrooks8/Aeron,galderz/Aeron,galderz/Aeron,mikeb01/Aeron,gkamal/Aeron