Fix numeric selection from lunch menu

Bug: 318871826
Test: 'lunch' with no arguments, then select a lunch target with a
number.

Change-Id: I8418ef0415437548d1429ec7a2c239d8c5b615d5
diff --git a/envsetup.sh b/envsetup.sh
index 212ed9f..84a604c 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -788,7 +788,7 @@
         selection=aosp_arm-trunk_staging-eng
     elif (echo -n $answer | grep -q -e "^[0-9][0-9]*$")
     then
-        local choices=($(TARGET_BUILD_APPS= get_build_var COMMON_LUNCH_CHOICES))
+        local choices=($(TARGET_BUILD_APPS= TARGET_PRODUCT= TARGET_RELEASE= TARGET_BUILD_VARIANT= get_build_var COMMON_LUNCH_CHOICES 2>/dev/null))
         if [ $answer -le ${#choices[@]} ]
         then
             # array in zsh starts from 1 instead of 0.