Increase timeout in `SampleSessionApplicationTests` to fix flaky local
builds.

Closes gh-25903

Closes gh-25906

Closes gh-25902

This commit harmonizes our auto-configuration so that default converters
are configured the same way ElasticsearchConfigurationSupport does.

Closes gh-25087

Closes gh-25843

Fixes gh-21478

Closes gh-25949

Closes gh-25948

Fixes gh-25948

* gh-25951:
  Upgrade to Gradle Enterprise Gradle Plugin 3.6.1

Closes gh-25951

See gh-25951

Previously, several tests in FileSystemWatcherTests assumed that all
of the changes detected by the watcher would be grouped into a single
change set. This assumption breaks down when a test runs slowly (due
to CPU or IO contention, for example), and making changes to the file
system takes long then the watcher's polling interval. When this
happens, the changes will be split across two (or more).

This commit attempts to make the tests more robust. The tests now
tolerate multiple changes sets by combining them and asserting that
across the n change sets, only the expected changes were detected.

Closes gh-25901

Closes gh-25978

Closes gh-25977

Closes gh-25976

Closes gh-25975

Closes gh-25974

Closes gh-25973

Closes gh-25972

Closes gh-25971

Closes gh-25970

Closes gh-25969

Closes gh-25968

Closes gh-25967

Closes gh-25966

Closes gh-25965

Closes gh-25964

Closes gh-25963

Closes gh-25962

Closes gh-25961

Closes gh-25960

Closes gh-25959

Closes gh-25958

Closes gh-25957

Closes gh-25956

Closes gh-25955

Closes gh-25954

Closes gh-25953

This commit copies the file mode along with other attributes when
copying files from the source archive to the build container while
building an image using the Gradle plugin. This preserves file
permissions on any resources included in the source archive.

Fixes gh-25915