Upgrade Java 15 CI image to use the Java 15 GA build

See gh-23391

Author: dreis2211

ci/images/get-jdk-url.sh

@@ -12,7 +12,7 @@ case "$1" in
 		 echo "https://github.com/AdoptOpenJDK/openjdk14-binaries/releases/download/jdk-14.0.2%2B12/OpenJDK14U-jdk_x64_linux_hotspot_14.0.2_12.tar.gz"
 	;;
 	java15)
-		 echo "https://github.com/AdoptOpenJDK/openjdk15-binaries/releases/download/jdk15u-2020-09-16-03-01/OpenJDK15U-jdk_x64_linux_hotspot_2020-09-16-03-01.tar.gz"
+		 echo "https://github.com/AdoptOpenJDK/openjdk15-binaries/releases/download/jdk-15%2B36/OpenJDK15U-jdk_x64_linux_hotspot_15_36.tar.gz"
 	;;
   *)
 		echo $"Unknown java version"

ci/scripts/detect-jdk-updates.sh

@@ -21,7 +21,7 @@ case "$JDK_VERSION" in
 		 ISSUE_TITLE="Upgrade Java 14 version in CI image"
 	;;
 	java15)
-		 BASE_URL="https://api.adoptopenjdk.net/v3/assets/feature_releases/15/ea"
+		 BASE_URL="https://api.adoptopenjdk.net/v3/assets/feature_releases/15/ga"
 		 ISSUE_TITLE="Upgrade Java 15 version in CI image"
 	;;
 	*)