Specify correct terminal to start the packager (#24436)

Summary:
This PR specifies the correct terminal to start the Metro bundler as stated in react-native-community/cli#303.

[iOS] [Changed] - Start the packager on the correct terminal.
Pull Request resolved: #24436

Differential Revision: D14932703

Pulled By: cpojer

fbshipit-source-id: 4c9b5a380ff4f4767acbeb6872e11e03df5b160c

Author: Lucas Bento

React/React.xcodeproj/project.pbxproj

@@ -3975,7 +3975,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "export RCT_METRO_PORT=\"${RCT_METRO_PORT:=8081}\"\necho \"export RCT_METRO_PORT=${RCT_METRO_PORT}\" > \"${SRCROOT}/../scripts/.packager.env\"\nif [ -z \"${RCT_NO_LAUNCH_PACKAGER+xxx}\" ] && [ \"$CONFIGURATION\" == \"Debug\" ] ; then\n  if nc -w 5 -z localhost ${RCT_METRO_PORT} ; then\n    if ! curl -s \"http://localhost:${RCT_METRO_PORT}/status\" | grep -q \"packager-status:running\" ; then\n      echo \"Port ${RCT_METRO_PORT} already in use, packager is either not running or not running correctly\"\n      exit 2\n    fi\n  else\n    open \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  fi\nfi\n";
+			shellScript = "terminal=\"${RCT_TERMINAL-${REACT_TERMINAL-$TERM_PROGRAM}}\"\n\nif [ -z \"${RCT_NO_LAUNCH_PACKAGER+xxx}\" ] ; then\n  if nc -w 5 -z localhost 8081 ; then\n    if ! curl -s \"http://localhost:8081/status\" | grep -q \"packager-status:running\" ; then\n      echo \"Port 8081 already in use, packager is either not running or not running correctly\"\n      exit 2\n    fi\n  elif [ -z \"$terminal\" ]; then\n    open \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  else\n    open -a $terminal \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  fi\nfi\n";
 			showEnvVarsInLog = 0;
 		};
 		142C4F7F1B582EA6001F0B58 /* Include RCTJSCProfiler */ = {
@@ -4095,7 +4095,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/sh;
-			shellScript = "if [ -z \"${RCT_NO_LAUNCH_PACKAGER+xxx}\" ] ; then\nif nc -w 5 -z localhost 8081 ; then\nif ! curl -s \"http://localhost:8081/status\" | grep -q \"packager-status:running\" ; then\necho \"Port 8081 already in use, packager is either not running or not running correctly\"\nexit 2\nfi\nelse\nopen \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\nfi\nfi\n";
+			shellScript = "terminal=\"${RCT_TERMINAL-${REACT_TERMINAL-$TERM_PROGRAM}}\"\n\nif [ -z \"${RCT_NO_LAUNCH_PACKAGER+xxx}\" ] ; then\n  if nc -w 5 -z localhost 8081 ; then\n    if ! curl -s \"http://localhost:8081/status\" | grep -q \"packager-status:running\" ; then\n      echo \"Port 8081 already in use, packager is either not running or not running correctly\"\n      exit 2\n    fi\n  elif [ -z \"$terminal\" ]; then\n    open \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  else\n    open -a $terminal \"$SRCROOT/../scripts/launchPackager.command\" || echo \"Can't start packager automatically\"\n  fi\nfi\n";
 			showEnvVarsInLog = 0;
 		};
 		3D383D3E1EBD27B9005632C8 /* Install Third Party */ = {