[ActivityManager] No home activity resumed and cause
key dispatch ANR

Symptom:
In some scenario, there might have two home tasks
in the home stack. If the top home task was finishing
and expected to return to home stack, no activity
will resume.

Root Cause:
Unable to perform resumeHomeStackTask() because the
resumeTopActivityLocked() has been prevented to invoke
recursively.

Solution:
Just resume the next activity if already in home stack

Change-Id: I24ecbcac6cee4ddbd90cdd27c4f4915cffb9b354
diff --git a/services/core/java/com/android/server/am/ActivityStack.java b/services/core/java/com/android/server/am/ActivityStack.java
index c03dbc2..152f8d7 100644
--- a/services/core/java/com/android/server/am/ActivityStack.java
+++ b/services/core/java/com/android/server/am/ActivityStack.java
@@ -1553,14 +1553,14 @@
                 // Now the task above it has to return to the home task instead.
                 final int taskNdx = mTaskHistory.indexOf(prevTask) + 1;
                 mTaskHistory.get(taskNdx).setTaskToReturnTo(HOME_ACTIVITY_TYPE);
-            } else {
-                if (DEBUG_STATES && isOnHomeDisplay()) Slog.d(TAG,
+            } else if (!isOnHomeDisplay()) {
+                return false;
+            } else if (!isHomeStack()){
+                if (DEBUG_STATES) Slog.d(TAG,
                         "resumeTopActivityLocked: Launching home next");
-                // Only resume home if on home display
                 final int returnTaskType = prevTask == null || !prevTask.isOverHomeStack() ?
                         HOME_ACTIVITY_TYPE : prevTask.getTaskToReturnTo();
-                return isOnHomeDisplay() &&
-                        mStackSupervisor.resumeHomeStackTask(returnTaskType, prev);
+                return mStackSupervisor.resumeHomeStackTask(returnTaskType, prev);
             }
         }