Fix auth_update if check

Author: pamelafox

scripts/auth_update.ps1

@@ -1,5 +1,5 @@
 $AZURE_USE_AUTHENTICATION = (azd env get-value AZURE_USE_AUTHENTICATION)
-if (-not $?) {
+if ($AZURE_USE_AUTHENTICATION -ne "true") {
   Exit 0
 }
 

scripts/auth_update.sh

@@ -1,7 +1,7 @@
  #!/bin/sh
 
 AZURE_USE_AUTHENTICATION=$(azd env get-value AZURE_USE_AUTHENTICATION)
-if [ $? -ne 0 ]; then
+if [ "$AZURE_USE_AUTHENTICATION" != "true" ]; then
   exit 0
 fi