[build infra] focal to use openjdk 11 instead of 17 to get rid of false errors (#2662)

* java 17

* use --debug for java gradle build

* add --debug

* update javadoc options within gradle

* revert back to jdk 11
diff --git a/lib/java/gradle/sourceConfiguration.gradle b/lib/java/gradle/sourceConfiguration.gradle
index 044a114..47f4ff0 100644
--- a/lib/java/gradle/sourceConfiguration.gradle
+++ b/lib/java/gradle/sourceConfiguration.gradle
@@ -53,6 +53,13 @@
     ]
 }
 
+tasks.withType(Javadoc) {
+    failOnError false
+    options.addStringOption('Xdoclint:none', '-quiet')
+    options.addStringOption('encoding', 'UTF-8')
+    options.addStringOption('charSet', 'UTF-8')
+}
+
 // ----------------------------------------------------------------------------
 // Jar packaging details
 processResources {