chore(java): pom generation to look at root versions.txt - #1706

chore(java): pom generation to look at root versions.txt#1706

suztomo merged 7 commits into

googleapis:mastergoogleapis/synthtool:masterfrom

suztomo:owlbot_java_monorepo_single_componentsuztomo/synthtool:owlbot_java_monorepo_single_componentCopy head branch name to clipboard