Include JAVA_ARGS_CLI example into /etc/default/puppetserver for Debian based systems

Puppet Server Version: 6.0.2-1bionic

OS Name/Version: Ubuntu 18.04

As https://puppet.com/docs/puppetserver/6.0/known_issues.html mentions

editing /etc/default/puppetserver JAVA_ARGS with -Djava.io.tmpdir=/some/other/temporary/directory enables puppetserver to start successfully.

However the sub commands (puppetserver gem install ...) use JAVA_ARGS_CLI and there is no mention of it in the puppetserver default file and Google is not cooperating thus taking a long time to troubleshoot.

Desired Behavior:

/etc/default/puppetserver to have an example for JAVA_ARGS_CLI

Actual Behavior:

In 18.04 if there is a security requirement to have noexec for /tmp mount

puppetserver gem install 'ANY_GEM' fails with the following stack trace

puppetserver gem install vault --no-ri --no-rdoc
io/console on JRuby shells out to stty for most operations
NotImplementedError: flock unsupported or native support failed to load; see http://wiki.jruby.org/Native-Libraries
flock at org/jruby/RubyFile.java:314
block in read_binary at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems.rb:851
open at org/jruby/RubyIO.java:1171
open at org/jruby/RubyKernel.java:307
read_binary at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems.rb:850
fetch_spec at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/source.rb:146
spec at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/resolver/api_specification.rb:77
add_always_install at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/resolver/installer_set.rb:78
resolve_dependencies at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/dependency_installer.rb:474
install_gem at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/install_command.rb:194
block in install_gems at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/install_command.rb:255
each at org/jruby/RubyArray.java:1735
install_gems at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/install_command.rb:251
execute at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/commands/install_command.rb:158
invoke_with_build_args at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/command.rb:310
process_args at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/command_manager.rb:169
run at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/command_manager.rb:139
run at uri:classloader:/META-INF/jruby.home/lib/ruby/stdlib/rubygems/gem_runner.rb:55
<main> at /opt/puppetlabs/server/apps/puppetserver/puppet-server-release.jar!/META-INF/jruby.home/bin/jgem:21
load at org/jruby/RubyKernel.java:974
<main> at /opt/puppetlabs/server/apps/puppetserver/puppet-server-release.jar!/META-INF/jruby.home/bin/gem:1
load at org/jruby/RubyKernel.java:974
<main> at -e:1