Test JDK version as part of PR builder [DI-317] (#816)

Adds additional assertion to the PR builder smoke test that the JDK is
the version expected for the image.

This is currently a _manual, post release_ check, moving earlier in the
cycle to catch defects earlier.

Fixes: [DI-317](https://hazelcast.atlassian.net/browse/DI-317)

Post merge actions:
- [ ] backport
- [ ] _Discuss_ if we remove the manual, post-release check?

[DI-317]:
https://hazelcast.atlassian.net/browse/DI-317?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

.github/scripts/simple-smoke-test.sh

@@ -29,6 +29,19 @@ function stop_container() {
     docker stop "${container_name}"
 }
 
+function check_java_version() {
+    local expected_major_version=$1
+    local actual_major_version
+    actual_major_version=$(docker run --rm "${image}" sh -c 'java -version 2>&1 | head -n 1 | awk -F "\"" "{print \$2}" | awk -F "." "{print \$1}"')
+
+    if [[ "${expected_major_version}" == "${actual_major_version}" ]]; then
+      echo "Expected Java version (${expected_distribution_type}) identified."
+    else
+      echoerr "Expected Java version '${expected_major_version}' but got '${actual_major_version}'"
+      exit 1;
+    fi
+}
+
 function derive_expected_distribution_type() {
   local input_distribution_type=$1
 
@@ -50,6 +63,7 @@ image=$1
 container_name=$2
 input_distribution_type=$3
 expected_version=$4
+expected_java_major_version=$5
 
 
 remove_container_if_exists
@@ -59,3 +73,4 @@ trap stop_container EXIT
 
 expected_distribution_type=$(derive_expected_distribution_type "${input_distribution_type}")
 test_package "${expected_distribution_type}" "${expected_version}"
+check_java_version "${expected_java_major_version}"