Revert "docker image: use JDK 11"

This reverts commit 90af396e47.

scripts/setup-ubuntu.sh

@@ -111,9 +111,6 @@ PACKAGES+=" libgmp-dev"
 PACKAGES+=" libunistring-dev"
 PACKAGES+=" llvm-9-dev"
 
-# Java.
-PACKAGES+=" openjdk-11-jdk"
-
 # Needed by packages in X11 repository.
 PACKAGES+=" docbook-xsl-ns"
 PACKAGES+=" gnome-common"
@@ -139,6 +136,28 @@ $SUDO apt-get -yq update
 $SUDO DEBIAN_FRONTEND=noninteractive \
 	apt-get install -yq --no-install-recommends $PACKAGES
 
+# Find and assign UBUNTU_VERSION
+if [[ `lsb_release -rs` == "19.04" ]]; then
+	UBUNTU_VERSION="19.04.2"
+else
+	UBUNTU_VERSION="18.10.1"
+fi
+
+# Make openjdk 8 available:
+curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jdk-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
+curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jdk_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
+curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
+curl -O http://security.ubuntu.com/ubuntu/pool/universe/o/openjdk-8/openjdk-8-jre-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
+$SUDO dpkg -i openjdk-8-jre-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
+	openjdk-8-jre_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
+	openjdk-8-jdk_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
+	openjdk-8-jdk-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb || $SUDO apt install -f -y
+
+rm openjdk-8-jre-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
+	openjdk-8-jre_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
+	openjdk-8-jdk_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb \
+	openjdk-8-jdk-headless_8u212-b03-0ubuntu1."$UBUNTU_VERSION"_amd64.deb
+
 $SUDO locale-gen --purge en_US.UTF-8
 echo -e 'LANG="en_US.UTF-8"\nLANGUAGE="en_US:en"\n' | $SUDO tee -a /etc/default/locale