Update Java JDK version

Author: SWilson4

ubuntu-latest/Dockerfile

@@ -16,6 +16,7 @@ RUN DEBIAN_FRONTEND=noninteractive TZ=Europe/Zurich && \
                        clang-format \
                        clang-tools \
                        cmake \
+                       default-jdk-headless \
                        docker.io \
                        gcc \
                        gcc-mingw-w64 \
@@ -41,7 +42,6 @@ RUN DEBIAN_FRONTEND=noninteractive TZ=Europe/Zurich && \
                        python3-jinja2 \
                        zlib1g-dev \
                        maven \
-                       openjdk-11-jdk \
                        valgrind \
                        flex bison \
                        lsb-release software-properties-common \
@@ -58,5 +58,8 @@ RUN opam init --yes --auto-setup && opam install --confirm-level=unsafe-yes --de
 # install ajv for CBOM validation
 RUN npm -g install ajv ajv-cli
 
+# set JAVA_HOME for liboqs-java builds
+ENV JAVA_HOME="/usr/lib/jvm/default-java"
+
 # Activate if we want to test specific OpenSSL3 versions:
 # RUN cd /root && git clone --depth 1 --branch openssl-3.0.7 https://github.com/openssl/openssl.git && cd openssl && LDFLAGS="-Wl,-rpath -Wl,/usr/local/openssl3/lib64"  ./config --prefix=/usr/local/openssl3 && make -j && make install