Add OpenJDK 20.0.1

Content of README.google:

Name: Java Development Kit (JDK)
URL: https://jdk.java.net/20/
Version: 20
Revision: NA
License: the GNU General Public License, version 2, with the Classpath Exception.

Description:
This is pulled directly from the website for the JDK releases that has an open source license.
Synlinks have reen resolved using `cp -rL` before uploading.

Bug: b/281902832
Change-Id: I5d4b3171e57ac0d16ba786a7156910947b5ab7be
diff --git a/scripts/add-openjdk.sh b/scripts/add-openjdk.sh
index e8714f3..4aac626 100755
--- a/scripts/add-openjdk.sh
+++ b/scripts/add-openjdk.sh
@@ -18,7 +18,7 @@
 
 # Now run script with fingers crossed!
 
-JDK_VERSION="18"
+JDK_VERSION="20.0.1"
 JDK_VERSION_FULL=${JDK_VERSION}
 # For ea versions the full version name has a postfix.
 # JDK_VERSION_FULL="${JDK_VERSION}-ea+33"