Running bash script in Post-Export method

I want to execute a bash script in OnPostProcessBuild() method , but my Unity Cloud build fails with below error logs :

! Unity player export failed! ! build of 'default_-android' failed. compile failed Publishing build 22 of .... for target 'default_-android'... publishing finished successfully. done. Build step 'Execute shell' marked build as failure postbuildstatus finished successfully. Finished: FAILURE

My Code is as below :

public class MyBuildPostprocessor : MonoBehaviour {

[PostProcessBuild]

 public static void OnPostProcessBuild(BuildTarget target, string pathToBuiltProject) { 
    String[] pathArr = pathToBuiltProject.Split ('/'); 
 String apkName = pathArr [pathArr.Length - 1]; 
 String apkPath = pathToBuiltProject.TrimEnd (apkName.ToCharArray());
 string scriptPath = Application.dataPath + "\\Plugins\\Android\\Editor\\PostProcessShellScript.sh\""; 
 RunInShell("open","\"" + scriptPath + " " + " " + "\"" + apkPath + "\""+ "\\ " + apkName, false);
 }
 public static void RunInShell(string file, string args, bool waitForExit = true) {     
 System.Diagnostics.Process ppScriptProcess = new System.Diagnostics.Process(); 
 ppScriptProcess.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Maximized; 
 ppScriptProcess.StartInfo.FileName = file; 
 ppScriptProcess.StartInfo.Arguments = args; 
 ppScriptProcess.StartInfo.UseShellExecute = false; 
 ppScriptProcess.StartInfo.CreateNoWindow = false; 
 ppScriptProcess.StartInfo.RedirectStandardOutput = true;
   ppScriptProcess.Start();}}