Fix Screen recorder not stopping

Summary:
This fixes the issue raised [here](https://fb.workplace.com/groups/flippersupport/permalink/1059080941239230/) I added the `-l` tag which is for sending signal

{F360746398}

Reviewed By: jknoxville

Differential Revision: D25945336

fbshipit-source-id: a1d8eaf3888072a64ab682fbbc60c03c15ac023a

desktop/app/src/devices/AndroidDevice.tsx

@@ -195,7 +195,7 @@ export default class AndroidDevice extends BaseDevice {
     if (!recordingProcess) {
       return Promise.reject(new Error('Recording was not properly started'));
     }
-    await this.adb.shell(this.serial, `pkill -2 screenrecord`);
+    await this.adb.shell(this.serial, `pkill -l2 screenrecord`);
     const destination = await recordingProcess;
     this.recordingProcess = undefined;
     return destination;