Add preview.5 to changelog.md

Author: heyams

CHANGELOG.md

@@ -46,6 +46,11 @@
   ([#1254](https://github.com/microsoft/ApplicationInsights-Java/pull/1254))
 * Fix backoff condition so that retries will continue indefinitely
   ([#1253](https://github.com/microsoft/ApplicationInsights-Java/pull/1253))
+  
+# Version 3.0.0 Preview.5
+* Fix memory leak
+* Fix shutdown issue due to non-daemon thread
+* Fix backoff condition so that retries will continue indefinitely
 
 # Version 2.6.1
 * Fix shutdown issue due to non-daemon thread