Upgrade maven-javadoc-plugin to 2.9.1 (Fixes CVE)

(cherry picked from commit 4c7969368a488a45e1b66346aefbcaf02f47f7d9)
[datastores][common] Install/deploy -tests.jar for the mini testing framework

(cherry picked from commit 3ebf7ac346d6193bba22995f361c430e63c8baa1)