Bump xstream from 1.4.8 to 1.4.15 in /test-utils#30

dependabot[bot] wants to merge 1 commit intomastertestusr/Experiments:masterfrom

dependabot/maven/test-utils/com.thoughtworks.xstream-xstream-1.4.15testusr/Experiments:dependabot/maven/test-utils/com.thoughtworks.xstream-xstream-1.4.15Copy head branch name to clipboard