This commit addresses an issue when trying to using Elasticsearch on
systems with Sys V init and the bundled JDK was not being used. Instead,
we were still inadvertently trying to fallback on the path. This commit
removes that fallback as that is against our intentions for 7.x where we
only support the bundled JDK or an explicit JDK via JAVA_HOME.
The system level tests for our distributions have historically be run in
vagrant, and thus the name of the gradle project has been "vagrant".
However, as we move to running these tests in other environments (eg
GCP) the name vagrant no longer makes sense. This commit renames the
project to "os" (short for operating system), since these tests ensure
all of our distributions run correctly on our supported operating
systems.
Jason Tedor
Ryan Ernst