Evergreen: Fix setting JAVA_HOME setting

run-mongodb-aws-ecs-test.sh can install jdk, so don't set the
JAVA_HOME if the expected location doesn't exist.

JAVA-4401 JAVA-4357

Author: rozza

.evergreen/javaConfig.bash

@@ -4,7 +4,10 @@
 export JDK8="/opt/java/jdk8"
 export JDK11="/opt/java/jdk11"
 export JDK17="/opt/java/jdk17"
-export JAVA_HOME=$JDK11
+
+if [ -d "$JDK11" ]; then
+  export JAVA_HOME=$JDK11
+fi
 
 export JAVA_VERSION=${JDK:-11}
 

.evergreen/run-mongodb-aws-ecs-test.sh

@@ -12,8 +12,6 @@ set -o errexit  # Exit the script with error if any of the commands fail
 ############################################
 #            Main Program                  #
 ############################################
-RELATIVE_DIR_PATH="$(dirname "${BASH_SOURCE:-$0}")"
-. "${RELATIVE_DIR_PATH}/javaConfig.bash"
 
 if [[ -z "$1" ]]; then
     echo "usage: $0 <MONGODB_URI>"
@@ -36,6 +34,10 @@ if ! which git ; then
 fi
 
 cd src
+
+RELATIVE_DIR_PATH="$(dirname "${BASH_SOURCE:-$0}")"
+. "${RELATIVE_DIR_PATH}/javaConfig.bash"
+
 ./gradlew -version
 
 echo "Running tests..."