title: PendingIntent issue building React Native app for Android 12 (FLAG_IMMUTABLE)
body: <p>Recently found out our app wasnt working for Android 12 users.</p>
  <p>So I updated compileSdkVersion and buildToolsVersion to 31 and finally have it building..</p>
  <p>Now when building it installs but crashes on start up. In logcat I found the following:</p>
  <pre><code>2021-10-30 17:17:56.596 17563-17587/com.walkabout.app E/AndroidRuntime: FATAL EXCEPTION: pool-4-thread-1
      Process: com.walkabout.app, PID: 17563
      java.lang.IllegalArgumentException: com.walkabout.app: Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.
      Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.
          at android.app.PendingIntent.checkFlags(PendingIntent.java:375)
          at android.app.PendingIntent.getBroadcastAsUser(PendingIntent.java:645)
          at android.app.PendingIntent.getBroadcast(PendingIntent.java:632)
          at androidx.work.impl.utils.ForceStopRunnable.getPendingIntent(ForceStopRunnable.java:273)
          at androidx.work.impl.utils.ForceStopRunnable.isForceStopped(ForceStopRunnable.java:151)
          at androidx.work.impl.utils.ForceStopRunnable.forceStopRunnable(ForceStopRunnable.java:171)
          at androidx.work.impl.utils.ForceStopRunnable.run(ForceStopRunnable.java:102)
          at androidx.work.impl.utils.SerialExecutor$Task.run(SerialExecutor.java:91)
          at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
          at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
          at java.lang.Thread.run(Thread.java:920)
  
  </code></pre>
  <p>I found 2 dependencies that did use pendingIntent, so I updated to the latest versions but no luck, still the same error.</p>
  <p>So I just removed those, then searched the entire project directory for pendingIntent, and none exist. Cleaned the project, npm install, npx react-native run-android. Still the same issue.</p>
  <p>I'm not sure where to go from here, but I keep getting that error even though I cant find pendingIntent in any of my code or node_modules. Any help is appreciated!</p>