AppCenter Android Build - Custom shell script appcenter-post-clone script fails with command not found

Question

I am trying to build native android app on Azure AppCenter. I have custom appcenter-post-clone.sh to be executed just after the source code clone step. The script executes, but fails with command not found. Here is a sample script and error output.

appcenter-post-clone.sh

#!/usr/bin/env bash

set -x
ls
pwd
ls -l

Build output

==============================================================================
Task         : Shell script
Description  : Run a shell script using Bash
Version      : 2.165.2
Author       : Microsoft Corporation
Help         : https://learn.microsoft.com/azure/devops/pipelines/tasks/utility/shell-script
==============================================================================
[command]/bin/bash /Users/runner/work/1/s/app/appcenter-post-clone.sh
/Users/runner/work/1/s/app/appcenter-post-clone.sh: line 2: 
: command not found
/Users/runner/work/1/s/app/appcenter-post-clone.sh: line 3: set: -
: invalid option
set: usage: set [--abefhkmnptuvxBCHP] [-o option] [arg ...]
/Users/runner/work/1/s/app/appcenter-post-clone.sh: line 5: ls
: command not found
/Users/runner/work/1/s/app/appcenter-post-clone.sh: line 6: pwd
: command not found
/Users/runner/work/1/s/app/appcenter-post-clone.sh: line 7: ls
: command not found
ls: illegal option -- 
usage: ls [-@ABCFGHLOPRSTUWabcdefghiklmnopqrstuwx1%] [file ...]

The pipeline is running on a mac agent. I do not understand if I am using the correct bash shell to execute the scripts.