Revert "Temporary logging to debug ActivityStarter crash."

Bug: 26541093

This reverts commit 7fca6d50a5.

Change-Id: I41fb70e79f2da6523c40f09a74d1980cbeb2149e

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

@@ -41,7 +41,6 @@ import android.graphics.Point;
 import android.graphics.Rect;
 import android.util.ArraySet;
 
-import android.util.Log;
 import com.android.internal.app.IVoiceInteractor;
 import com.android.internal.content.ReferrerIntent;
 import com.android.internal.os.BatteryStatsImpl;
@@ -4713,7 +4712,6 @@ final class ActivityStack {
         }
 
         task.stack = null;
-        task.lastStackClear = Log.getStackTraceString(new Throwable());
     }
 
     TaskRecord createTaskRecord(int taskId, ActivityInfo info, Intent intent,

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

@@ -1280,10 +1280,6 @@ class ActivityStarter {
     }
 
     private ActivityRecord setTargetStackAndMoveToFrontIfNeeded(ActivityRecord intentActivity) {
-        if (intentActivity.task.stack == null) {
-            Slog.wtf(TAG, "Oops, the stack is null, we are about to crash. It was last cleared: "
-                    + intentActivity.task.lastStackClear);
-        }
         mTargetStack = intentActivity.task.stack;
         mTargetStack.mLastPausedActivity = null;
         // If the target task is not in the front, then we need to bring it to the front...

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

@@ -245,8 +245,6 @@ final class TaskRecord {
     int mLayerRank = -1;
 
     Configuration mOverrideConfig = Configuration.EMPTY;
-    // STOPSHIP(b/26541093)
-    public String lastStackClear = "UNSET";
 
     TaskRecord(ActivityManagerService service, int _taskId, ActivityInfo info, Intent _intent,
             IVoiceInteractionSession _voiceSession, IVoiceInteractor _voiceInteractor) {