Fix iOS screen recording

Summary: It looks like the iOS simulator screen recording tool expects a SIGINT instead of a SIGKILL (the default of node's ChildProcess.kill()) to indicate it should stop recording, save the video file and die cleanly.

Reviewed By: danielbuechele

Differential Revision: D9480678

fbshipit-source-id: 5f17bd288c7622ffa3c337cef311e5e4e462218a

src/chrome/ScreenCaptureButtons.js

@@ -232,7 +232,7 @@ class ScreenCaptureButtons extends Component<Props, State> {
     if (selectedDevice instanceof AndroidDevice) {
       this.executeShell(selectedDevice, `pgrep 'screenrecord' -L 2`);
     } else if (this.iOSRecorder && videoPath) {
-      this.iOSRecorder.kill();
+      this.iOSRecorder.kill('SIGINT');
       this.setState({
         recording: false,
       });