The background Gradle daemon run for supporting Gradle projects doesn't respect system settings.

Environment

• Operating System: ArchLinux, Windows
• JDK version: 8.0.121-b13
• Visual Studio Code version: 1.12.2
• Java extension version: 0.5.0

Steps To Reproduce

1. Open VSCode
2. Open a Gradle-based Java project

Current Result

You can find a running Gradle instance in such a way

$ pgrep -f -a gradle
22406 /usr/lib/jvm/java-8-openjdk/bin/java -XX:MaxPermSize=256m -XX:+HeapDumpOnOutOfMemoryError -Xmx1024m -Dfile.encoding=UTF-8 -Duser.country=IT -Duser.language=it -Duser.variant -cp /user/home/.gradle/wrapper/dists/gradle-3.5-bin/daoimhu7k5rlo48ntmxw2ok3e/gradle-3.5/lib/gradle-launcher-3.5.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 3.5

Expected Result

1. If available, system Gradle should be run
2. Gradle should respect defined variables

Additional Informations

The Gradle options I would like to be respected are these ones:
export GRADLE_OPTS="-Xmx64m -Dorg.gradle.jvmargs='-Xmx256m -XX:MaxPermSize=64m'"
Running Gradle from a terminal does respect them.