Artifact permissions are not preserved for local agents

Summary

Artifact permissions are not preserved for local agents as BAM-17770.

Environment

Tested in the Ubuntu-based docker container – atlassian/bamboo-server.

Steps to Reproduce

1. create a new Project (i.e.: Support), Plan (i.e.: MyPlan)
2. add an "Script" task

   # creates a new file
   touch index.html
   
   # list files
   ls -l
   
   # change its permission
   chmod 777 index.html
   
   # list files
   ls -l
   

   As a result you would have something like:

   25-Dec-2018 08:00:55	total 0
   25-Dec-2018 08:00:55	-rw-r----- 1 bamboo bamboo 0 Dec 25 08:00 index.html
   25-Dec-2018 08:00:55	total 0
   25-Dec-2018 08:00:55	-rwxrwxrwx 1 bamboo bamboo 0 Dec 25 08:00 index.html
   

3. create an Artifact definition as per following:

   Name: myArtifact
   Location:
   Copy pattern: executable.jar
   [x] Shared
   

4. go to $BAMBOO_HOME/artifacts and run the following:

   ls -l SUP-MYPLAN/shared/build-00001/myArtifact/index.html
   

As a result you would have something like:

-rwxr-x--x 1 bamboo bamboo 0 Dec 25 07:52 <SUP-MYPLAN>/shared/build-00001/myArtifact/index.html

Workaround

Same as BAM-17770