Use runtimeJar configuration instead of default for plugin markers.

(cherry picked from commit d453a2f)

libraries/tools/gradle-tools/pluginMarkers.gradle

@@ -14,7 +14,7 @@ ext.pluginMarkerProject = { String pluginProjectId ->
     apply plugin: 'java'
 
     dependencies {
-        compile pluginProject
+        compile project(path: pluginProject.path, configuration: 'runtimeJar')
     }
 
     // Remove the default JAR artifact added by the Java plugin