Increase timeout for branch (#5667)

Jenkinsfile

@@ -36,7 +36,7 @@ for(j = 0; j < jdks.size(); j++) {
 
                 // Now run the actual build.
                 stage("${buildType} Build / Test") {
-                    timeout(time: 180, unit: 'MINUTES') {
+                    timeout(time: 300, unit: 'MINUTES') {
                         // See below for what this method does - we're passing an arbitrary environment
                         // variable to it so that JAVA_OPTS and MAVEN_OPTS are set correctly.
                         withMavenEnv(["JAVA_OPTS=-Xmx1536m -Xms512m",