I am such an idiot.

Seriously, don't look at this.  It is so dumb.

Brought up by issue #17307700: retarget a relinquished
task is not working

Change-Id: I947438d3502f75510e2974211bb78d31008eaa90

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

@@ -18966,6 +18966,7 @@ public final class ActivityManagerService extends ActivityManagerNative
                 }
                 if (tr.getRootActivity() != null) {
                     moveTaskToFrontLocked(tr.taskId, 0, null);
+                    return;
                 }
             }