diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/Extensions.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/Extensions.kt
deleted file mode 100644
index 1869d833fbc43..0000000000000
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/Extensions.kt
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (C) 2021 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-@file:JvmName("Utils")
-package com.android.wm.shell.flicker
-
-import android.app.ActivityTaskManager
-import android.app.WindowConfiguration.ACTIVITY_TYPE_ASSISTANT
-import android.app.WindowConfiguration.ACTIVITY_TYPE_RECENTS
-import android.app.WindowConfiguration.ACTIVITY_TYPE_STANDARD
-import android.app.WindowConfiguration.ACTIVITY_TYPE_UNDEFINED
-
-fun removeAllTasksButHome() {
-    val ALL_ACTIVITY_TYPE_BUT_HOME = intArrayOf(
-        ACTIVITY_TYPE_STANDARD, ACTIVITY_TYPE_ASSISTANT, ACTIVITY_TYPE_RECENTS,
-        ACTIVITY_TYPE_UNDEFINED)
-    val atm = ActivityTaskManager.getService()
-    atm.removeRootTasksWithActivityTypes(ALL_ACTIVITY_TYPE_BUT_HOME)
-}
diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipLegacySplitScreenTest.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipLegacySplitScreenTest.kt
index 6166721448c91..afba508f54b74 100644
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipLegacySplitScreenTest.kt
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipLegacySplitScreenTest.kt
@@ -29,7 +29,7 @@ import com.android.server.wm.flicker.helpers.wakeUpAndGoToHomeScreen
 import com.android.wm.shell.flicker.helpers.ImeAppHelper
 import com.android.wm.shell.flicker.helpers.FixedAppHelper
 import com.android.server.wm.flicker.repetitions
-import com.android.wm.shell.flicker.removeAllTasksButHome
+import com.android.server.wm.flicker.rules.RemoveAllTasksButHomeRule.Companion.removeAllTasksButHome
 import com.android.wm.shell.flicker.testapp.Components.PipActivity.EXTRA_ENTER_PIP
 import org.junit.FixMethodOrder
 import org.junit.Test
diff --git a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipTransition.kt b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipTransition.kt
index f8856827ff425..ad1ccbd107532 100644
--- a/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipTransition.kt
+++ b/libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipTransition.kt
@@ -33,12 +33,12 @@ import com.android.server.wm.flicker.navBarLayerRotatesAndScales
 import com.android.server.wm.flicker.navBarWindowIsAlwaysVisible
 import com.android.server.wm.flicker.noUncoveredRegions
 import com.android.server.wm.flicker.repetitions
+import com.android.server.wm.flicker.rules.RemoveAllTasksButHomeRule.Companion.removeAllTasksButHome
 import com.android.server.wm.flicker.startRotation
 import com.android.server.wm.flicker.statusBarLayerIsAlwaysVisible
 import com.android.server.wm.flicker.statusBarLayerRotatesScales
 import com.android.server.wm.flicker.statusBarWindowIsAlwaysVisible
 import com.android.wm.shell.flicker.helpers.PipAppHelper
-import com.android.wm.shell.flicker.removeAllTasksButHome
 import com.android.wm.shell.flicker.testapp.Components
 import org.junit.Test
 
diff --git a/tests/FlickerTests/AndroidManifest.xml b/tests/FlickerTests/AndroidManifest.xml
index 19429434fe5f2..fda6091964569 100644
--- a/tests/FlickerTests/AndroidManifest.xml
+++ b/tests/FlickerTests/AndroidManifest.xml
@@ -38,6 +38,8 @@
     <!-- Workaround grant runtime permission exception from b/152733071 -->
     <uses-permission android:name="android.permission.PACKAGE_USAGE_STATS"/>
     <uses-permission android:name="android.permission.READ_LOGS"/>
+    <!-- ATM.removeRootTasksWithActivityTypes() -->
+    <uses-permission android:name="android.permission.MANAGE_ACTIVITY_TASKS" />
     <!-- Allow the test to write directly to /sdcard/ -->
     <application android:requestLegacyExternalStorage="true">
         <uses-library android:name="android.test.runner"/>
diff --git a/tests/FlickerTests/src/com/android/server/wm/flicker/launch/OpenAppColdTest.kt b/tests/FlickerTests/src/com/android/server/wm/flicker/launch/OpenAppColdTest.kt
index a3d1395a680a7..024983d68b214 100644
--- a/tests/FlickerTests/src/com/android/server/wm/flicker/launch/OpenAppColdTest.kt
+++ b/tests/FlickerTests/src/com/android/server/wm/flicker/launch/OpenAppColdTest.kt
@@ -24,6 +24,7 @@ import com.android.server.wm.flicker.FlickerTestParameterFactory
 import com.android.server.wm.flicker.helpers.setRotation
 import com.android.server.wm.flicker.startRotation
 import com.android.server.wm.flicker.dsl.FlickerBuilder
+import com.android.server.wm.flicker.rules.RemoveAllTasksButHomeRule.Companion.removeAllTasksButHome
 import org.junit.FixMethodOrder
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -44,6 +45,7 @@ class OpenAppColdTest(testSpec: FlickerTestParameter) : OpenAppTransition(testSp
             super.transition(this, it)
             setup {
                 eachRun {
+                    removeAllTasksButHome()
                     this.setRotation(testSpec.config.startRotation)
                 }
             }