Backport of #48849. Update `.editorconfig` to make the Java settings the
default for all files, and then apply a 2-space indent to all `*.gradle`
files. Then reformat all the files.
Move `x-pack/qa/smoke-test-graph-with-security` to
`x-pack/plugin/graph/qa/security` which should make it easier to run all
of the tests with a single command. It also lines up the directories
more closely with newer projects like cross cluster replication.