Clarify support for bundled JDK (#113993) (#114209)

Spells out that third-party EOL schedules don't affect our support. Also
reorders the information to talk about the benefits of the bundled JDK
before mentioning alternatives, and clarifies the division of
responsibilities for "supported" JDKs other than the bundled one.

Author: DaveCTurner

docs/reference/setup/install.asciidoc

@@ -76,27 +76,29 @@ Docker container images may be downloaded from the Elastic Docker Registry.
 [[jvm-version]]
 === Java (JVM) Version
 
-{es} is built using Java, and includes a bundled version of
-https://openjdk.java.net[OpenJDK] from the JDK maintainers (GPLv2+CE) within
-each distribution. The bundled JVM is the recommended JVM.
-
-To use your own version of Java, set the `ES_JAVA_HOME` environment variable.
-If you must use a version of Java that is different from the bundled JVM, it is
-best to use the latest release of a link:/support/matrix[supported]
-https://www.oracle.com/technetwork/java/eol-135779.html[LTS version of Java].
-{es} is closely coupled to certain OpenJDK-specific features, so it may not
-work correctly with other JVMs. {es} will refuse to start if a known-bad
-version of Java is used.
-
-If you use a JVM other than the bundled one, you are responsible for reacting
-to announcements related to its security issues and bug fixes, and must
-yourself determine whether each update is necessary or not. In contrast, the
-bundled JVM is treated as an integral part of {es}, which means that Elastic
-takes responsibility for keeping it up to date. Security issues and bugs within
-the bundled JVM are treated as if they were within {es} itself.
-
-The bundled JVM is located within the `jdk` subdirectory of the {es} home
-directory. You may remove this directory if using your own JVM.
+{es} is built using Java, and includes a bundled version of https://openjdk.java.net[OpenJDK] within each distribution. We strongly
+recommend using the bundled JVM in all installations of {es}.
+
+The bundled JVM is treated the same as any other dependency of {es} in terms of support and maintenance. This means that Elastic takes
+responsibility for keeping it up to date, and reacts to security issues and bug reports as needed to address vulnerabilities and other bugs
+in {es}. Elastic's support of the bundled JVM is subject to Elastic's https://www.elastic.co/support_policy[support policy] and
+https://www.elastic.co/support/eol[end-of-life schedule] and is independent of the support policy and end-of-life schedule offered by the
+original supplier of the JVM. Elastic does not support using the bundled JVM for purposes other than running {es}.
+
+TIP: {es} uses only a subset of the features offered by the JVM. Bugs and security issues in the bundled JVM often relate to features that
+{es} does not use. Such issues do not apply to {es}. Elastic analyzes reports of security vulnerabilities in all its dependencies, including
+in the bundled JVM, and will issue an https://www.elastic.co/community/security[Elastic Security Advisory] if such an advisory is needed.
+
+If you decide to run {es} using a version of Java that is different from the bundled one, prefer to use the latest release of a
+https://www.oracle.com/technetwork/java/eol-135779.html[LTS version of Java] which is link:/support/matrix[listed in the support matrix].
+Although such a configuration is supported, if you encounter a security issue or other bug in your chosen JVM then Elastic may not be able
+to help unless the issue is also present in the bundled JVM. Instead, you must seek assistance directly from the supplier of your chosen
+JVM. You must also take responsibility for reacting to security and bug announcements from the supplier of your chosen JVM. {es} may not
+perform optimally if using a JVM other than the bundled one. {es} is closely coupled to certain OpenJDK-specific features, so it may not
+work correctly with JVMs that are not OpenJDK. {es} will refuse to start if you attempt to use a known-bad JVM version.
+
+To use your own version of Java, set the `ES_JAVA_HOME` environment variable to the path to your own JVM installation. The bundled JVM is
+located within the `jdk` subdirectory of the {es} home directory. You may remove this directory if using your own JVM.
 
 [discrete]
 [[jdk-locale]]