Generate ip.txt before SKIP_BUNDLING check (#20554)

Summary:
Fixes #20553.

Re-applies the change as described in https://github.com/facebook/react-native/pull/16533, which was closed for being stale. Thanks to emusgrave for the original PR/change.
Pull Request resolved: https://github.com/facebook/react-native/pull/20554

Differential Revision: D9414933

Pulled By: hramos

fbshipit-source-id: 8ebca57e32b905c4ecfd661524ca415f51162545

scripts/react-native-xcode.sh

@@ -8,6 +8,20 @@
 # This script is supposed to be invoked as part of Xcode build process
 # and relies on environment variables (including PWD) set by Xcode
 
+# Print commands before executing them (useful for troubleshooting)
+set -x
+DEST=$CONFIGURATION_BUILD_DIR/$UNLOCALIZED_RESOURCES_FOLDER_PATH
+
+# Enables iOS devices to get the IP address of the machine running Metro Bundler
+if [[ "$CONFIGURATION" = *Debug* && ! "$PLATFORM_NAME" == *simulator ]]; then
+  IP=$(ipconfig getifaddr en0)
+  if [ -z "$IP" ]; then
+    IP=$(ifconfig | grep 'inet ' | grep -v ' 127.' | cut -d\   -f2  | awk 'NR==1{print $1}')
+  fi
+
+  echo "$IP" > "$DEST/ip.txt"
+fi
+
 if [[ "$SKIP_BUNDLING" ]]; then
   echo "SKIP_BUNDLING enabled; skipping."
   exit 0;
@@ -90,19 +104,6 @@ nodejs_not_found()
 
 type $NODE_BINARY >/dev/null 2>&1 || nodejs_not_found
 
-# Print commands before executing them (useful for troubleshooting)
-set -x
-DEST=$CONFIGURATION_BUILD_DIR/$UNLOCALIZED_RESOURCES_FOLDER_PATH
-
-if [[ "$CONFIGURATION" = *Debug* && ! "$PLATFORM_NAME" == *simulator ]]; then
-  IP=$(ipconfig getifaddr en0)
-  if [ -z "$IP" ]; then
-    IP=$(ifconfig | grep 'inet ' | grep -v ' 127.' | cut -d\   -f2  | awk 'NR==1{print $1}')
-  fi
-
-  echo "$IP" > "$DEST/ip.txt"
-fi
-
 BUNDLE_FILE="$DEST/main.jsbundle"
 
 $NODE_BINARY "$CLI_PATH" $BUNDLE_COMMAND \