Fix packaging service check failures (#15946) (#15949)

This commit tightens the checks for the status
output of the Logstash OS service to specifically
scan for `org.logstash.Logstash` rather than
only the jdk path.

The reason is that the startup script first runs
an options parser, and then the logstash process
itself, both referencing the JDK path.

Closes https://github.com/elastic/ingest-dev/issues/2950

(cherry picked from commit eedccea33f)

Co-authored-by: Dimitrios Liappis <dimitrios.liappis@gmail.com>

qa/rspec/commands/system_helpers.rb

@@ -26,7 +26,7 @@ module ServiceTester
       stdout.force_encoding(Encoding::UTF_8)
       (
         stdout.match(/Active: active \(running\)/) &&
-        stdout.match(/^\s*(└─|`-)\d*\s.*#{jdk_path}/) &&
+        stdout.match(/^\s*(└─|`-)\d*\s.*#{jdk_path}.*org\.logstash\.Logstash/) &&
         stdout.match(/#{package}.service - #{package}/)
       )
     end