pshell 7.4 somehow caused git show to stop working. this update resol…

…ves the problem (Azure#35033)

Co-authored-by: Scott Beddall (from Dev Box) <[email protected]>

eng/common/scripts/Helpers/git-helpers.ps1

@@ -65,8 +65,9 @@ class ConflictedFile {
       # powershell ignores the newlines with and without --textconv, which results in a json file without original spacing.
       # by forcefully reading into the array line by line, the whitespace is preserved. we're relying on gits autoconverstion of clrf to lf
       # to ensure that the line endings are consistent.
-      Write-Host "git show $($this.LeftSource):$($this.Path)"
-      $tempContent = git show ("$($this.LeftSource):$($this.Path)")
+      $toShow = "$($this.LeftSource):$($this.Path)" -replace "\\", "/"
+      Write-Host "git show $toShow"
+      $tempContent = git show $toShow
       return $tempContent -split "`r?`n"
     }
     else {
@@ -76,8 +77,9 @@ class ConflictedFile {
 
   [array] Right(){
     if ($this.IsConflicted) {
-      Write-Host "git show $($this.RightSource):$($this.Path)"
-      $tempContent =  git show ("$($this.RightSource):$($this.Path)")
+      $toShow = "$($this.RightSource):$($this.Path)" -replace "\\", "/"
+      Write-Host "git show $toShow"
+      $tempContent = git show $toShow
       return $tempContent -split "`r?`n"
     }
     else {