title: Unable to run Trusted Web Activity after upgrading to Android 12 (SDK 31)
body: <p>Recently we are preparing for Android 12 and we updated our compileSdkVersion and targetSdkVersion to 31
  After updating to 31, TWA is unable to be launched. Error given is</p>
  <pre><code>    java.lang.IllegalArgumentException: xxx.twa: 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.getActivityAsUser(PendingIntent.java:458)
          at android.app.PendingIntent.getActivity(PendingIntent.java:444)
          at android.app.PendingIntent.getActivity(PendingIntent.java:408)
          at androidx.browser.customtabs.CustomTabsClient.createSessionId(CustomTabsClient.java:231)
          at androidx.browser.customtabs.CustomTabsClient.newSession(CustomTabsClient.java:269)
          at com.google.androidbrowserhelper.trusted.TwaLauncher$TwaCustomTabsServiceConnection.onCustomTabsServiceConnected(TwaLauncher.java:324)
          at androidx.browser.customtabs.CustomTabsServiceConnection.onServiceConnected(CustomTabsServiceConnection.java:57)
          at android.app.LoadedApk$ServiceDispatcher.doConnected(LoadedApk.java:2077)
          at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:2110)
          at android.os.Handler.handleCallback(Handler.java:938)
          at android.os.Handler.dispatchMessage(Handler.java:99)
          at android.os.Looper.loopOnce(Looper.java:201)
          at android.os.Looper.loop(Looper.java:288)
          at android.app.ActivityThread.main(ActivityThread.java:7842)
          at java.lang.reflect.Method.invoke(Native Method)
          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
  </code></pre>
  <p>After updating androidx.browser:browser <code>implementation 'androidx.browser:browser:1.4.0-beta01'</code> i got the below error</p>
  <pre><code>    java.lang.IllegalArgumentException: xxx.twa: Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.
      Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.
          at android.app.PendingIntent.checkFlags(PendingIntent.java:375)
          at android.app.PendingIntent.getActivityAsUser(PendingIntent.java:458)
          at android.app.PendingIntent.getActivity(PendingIntent.java:444)
          at android.app.PendingIntent.getActivity(PendingIntent.java:408)
          at com.google.androidbrowserhelper.trusted.FocusActivity.addToIntent(FocusActivity.java:43)
          at com.google.androidbrowserhelper.trusted.TwaLauncher.launchWhenSplashScreenReady(TwaLauncher.java:272)
          at com.google.androidbrowserhelper.trusted.TwaLauncher.lambda$launchWhenSessionEstablished$4$TwaLauncher(TwaLauncher.java:257)
          at com.google.androidbrowserhelper.trusted.-$$Lambda$TwaLauncher$6zo6viK_vVSs4bt2THXs48ruews.run(Unknown Source:6)
          at com.google.androidbrowserhelper.trusted.splashscreens.PwaWrapperSplashScreenStrategy.lambda$onSplashImageTransferred$1$PwaWrapperSplashScreenStrategy(PwaWrapperSplashScreenStrategy.java:208)
          at com.google.androidbrowserhelper.trusted.splashscreens.-$$Lambda$PwaWrapperSplashScreenStrategy$p-f_rUE4TsZEGw17K3MBDrUxlsQ.run(Unknown Source:4)
          at com.google.androidbrowserhelper.trusted.splashscreens.PwaWrapperSplashScreenStrategy.runWhenEnterAnimationComplete(PwaWrapperSplashScreenStrategy.java:215)
          at com.google.androidbrowserhelper.trusted.splashscreens.PwaWrapperSplashScreenStrategy.onSplashImageTransferred(PwaWrapperSplashScreenStrategy.java:207)
          at com.google.androidbrowserhelper.trusted.splashscreens.PwaWrapperSplashScreenStrategy.lambda$configureTwaBuilder$0$PwaWrapperSplashScreenStrategy(PwaWrapperSplashScreenStrategy.java:195)
          at com.google.androidbrowserhelper.trusted.splashscreens.-$$Lambda$PwaWrapperSplashScreenStrategy$AEuRt7oVnGOP2vf-Uvl2RaqkFW4.onFinished(Unknown Source:6)
          at com.google.androidbrowserhelper.trusted.splashscreens.SplashImageTransferTask$1.onPostExecute(SplashImageTransferTask.java:144)
          at com.google.androidbrowserhelper.trusted.splashscreens.SplashImageTransferTask$1.onPostExecute(SplashImageTransferTask.java:91)
          at android.os.AsyncTask.finish(AsyncTask.java:771)
          at android.os.AsyncTask.access$900(AsyncTask.java:199)
          at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:788)
          at android.os.Handler.dispatchMessage(Handler.java:106)
          at android.os.Looper.loopOnce(Looper.java:201)
          at android.os.Looper.loop(Looper.java:288)
          at android.app.ActivityThread.main(ActivityThread.java:7842)
          at java.lang.reflect.Method.invoke(Native Method)
          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
  </code></pre>
  <p>I tried to find an updated version of com.google.androidbrowserhelper but is unable to find any. I am currently using <code>implementation 'com.google.androidbrowserhelper:androidbrowserhelper:2.2.2'</code></p>
  <p>Have anyone encounter this and is able to help?</p>