Resume app switching if activity is start from recent

If app is started from recent, it doesn't go to regular startActivity
path, but it should still resume app switching feature.

Bug: 173509909
Test: atest ActivityStarterTests
Test: In gesture navigation mode, switch between apps, can see the
resume app swithcing api is called and apps are able to start activities
successfully.
Change-Id: I0c2e2d9083d48401c9e00159edb49ed8268a8248

services/core/java/com/android/server/wm/ActivityTaskSupervisor.java

@@ -2562,6 +2562,11 @@ public class ActivityTaskSupervisor implements RecentTasks.Callbacks {
                 mService.getActivityStartController().postStartActivityProcessingForLastStarter(
                         task.getTopNonFinishingActivity(), ActivityManager.START_TASK_TO_FRONT,
                         task.getRootTask());
+
+                // As it doesn't go to ActivityStarter.executeRequest() path, we need to resume
+                // app switching here also.
+                mService.resumeAppSwitches();
+
                 return ActivityManager.START_TASK_TO_FRONT;
             }
             callingPackage = task.mCallingPackage;