Update platform.ts

Author: SydneyhSmith

src/platform.ts

@@ -108,11 +108,11 @@ export function getDefaultPowerShellPath(
         return !platformDetails.isOS64Bit || platformDetails.isProcess64Bit
                  ? System32PowerShellPath
                  : SysnativePowerShellPath;
-    } if (platformDetails.operatingSystem === OperatingSystem.MacOS) {
+    }   if (platformDetails.operatingSystem === OperatingSystem.MacOS) {
         // Always default to the stable version of PowerShell (if installed) but handle case of only Preview installed
-        powerShellExePath = macOSExePath;
-        if (!fs.existsSync(macOSExePath) && fs.existsSync(macOSPreviewExePath)) {
-            powerShellExePath = macOSPreviewExePath;
+            powerShellExePath = macOSExePath;
+            if (!fs.existsSync(macOSExePath) && fs.existsSync(macOSPreviewExePath)) {
+                powerShellExePath = macOSPreviewExePath;
         }
     } else if (platformDetails.operatingSystem === OperatingSystem.Linux) {
         // Always default to the stable version of PowerShell (if installed) but handle case of only Preview installed