Merge "Block root task from being shown in recents" into pi-dev

services/core/java/com/android/server/am/LockTaskController.java

@@ -285,6 +285,16 @@ public class LockTaskController {
         return false;
     }
 
+    /**
+     * @return the root task of the lock task.
+     */
+    TaskRecord getRootTask() {
+        if (mLockTaskModeTasks.isEmpty()) {
+            return null;
+        }
+        return mLockTaskModeTasks.get(0);
+    }
+
     private boolean isLockTaskModeViolationInternal(TaskRecord task, boolean isNewClearTask) {
         // TODO: Double check what's going on here. If the task is already in lock task mode, it's
         // likely whitelisted, so will return false below.

services/core/java/com/android/server/am/RecentTasks.java

@@ -1155,6 +1155,11 @@ class RecentTasks {
                 }
         }
 
+        // If we're in lock task mode, ignore the root task
+        if (task == mService.mLockTaskController.getRootTask()) {
+            return false;
+        }
+
         return true;
     }