Log Docker output to aid debugging

Add an SLF4J logger so that we can see real time output of the
Docker container.

See gh-29370

src/checkstyle/checkstyle-suppressions.xml

@@ -52,4 +52,5 @@
 	<suppress files="StringSequence" checks="SpringMethodVisibility" message="isEmpty"/>
 	<suppress files="ValidatorPropertiesWithDefaultValues\.java" checks="SpringMethodVisibility" />
 	<suppress files="DevToolsR2dbcAutoConfigurationTests" checks="HideUtilityClassConstructor" />
+	<suppress files="AbstractLaunchScriptIntegrationTests" checks="IllegalImport" />
 </suppressions>