Upgrade Gradle Wrapper version to Gradle 3.2.1

Issue: SPR-14906

Author: jhoeller

build.gradle

@@ -1416,7 +1416,7 @@ configure(rootProject) {
 
 	task wrapper(type: Wrapper) {
 		description = "Generates gradlew[.bat] scripts"
-		gradleVersion = '3.0'
+		gradleVersion = '3.2.1'
 
 		doLast() {
 			def gradleOpts = "-XX:MaxMetaspaceSize=1024m -Xmx1024m"