4-2/ Enhance AbstractStandardAppHelper.exit() to exit PIP at end

Integrate forceStop() in exit() that PIP window could really
exit after each round of test

Bug: 173567664
Test: atest com.android.wm.shell.flicker
Test: atest com.android.server.wm.flicker.Flicker

Change-Id: I8aaa4f590344f8fb1e6e731ed865f21f63892bb2

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/apppairs/AppPairsTest.kt

@@ -70,8 +70,8 @@ class AppPairsTest(
                 eachRun {
                     executeShellCommand(composePairsCommand(
                             primaryTaskId, secondaryTaskId, false /* pair */))
-                    primaryApp.forceStop()
-                    secondaryApp.forceStop()
+                    primaryApp.exit()
+                    secondaryApp.exit()
                 }
             }
             assertions {

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/helpers/BaseAppHelper.kt

@@ -16,7 +16,6 @@
 
 package com.android.wm.shell.flicker.helpers
 
-import android.app.ActivityManager
 import android.app.Instrumentation
 import android.content.ComponentName
 import android.content.Context
@@ -46,9 +45,6 @@ abstract class BaseAppHelper(
     protected val context: Context
         get() = mInstrumentation.context
 
-    private val activityManager: ActivityManager?
-        get() = context.getSystemService(ActivityManager::class.java)
-
     private val appSelector = By.pkg(packageName).depth(0)
 
     protected val isTelevision: Boolean
@@ -77,10 +73,6 @@ abstract class BaseAppHelper(
         return uiDevice.wait(Until.gone(appSelector), APP_CLOSE_WAIT_TIME_MS)
     }
 
-    fun forceStop() {
-        activityManager?.forceStopPackage(packageName)
-    }
-
     override fun getOpenAppIntent(): Intent {
         val intent = Intent()
         intent.component = launcherActivityComponent

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/PipKeyboardTest.kt

@@ -76,12 +76,12 @@ class PipKeyboardTest(
             }
             teardown {
                 test {
-                    keyboardApp.forceStop()
+                    keyboardApp.exit()
 
                     if (device.hasPipWindow()) {
                         device.closePipWindow()
                     }
-                    testApp.forceStop()
+                    testApp.exit()
                     this.setRotation(Surface.ROTATION_0)
                 }
             }
@@ -210,4 +210,4 @@ class PipKeyboardTest(
             return supportedRotations.map { arrayOf(Surface.rotationToString(it), it) }
         }
     }
-}
+}

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/pip/tv/TvPipTestBase.kt

@@ -53,7 +53,7 @@ abstract class TvPipTestBase : PipTestBase(rotationToString(ROTATION_0), ROTATIO
     open fun tearDown() {
         if (!isTelevision) return
 
-        testApp.forceStop()
+        testApp.exit()
 
         // Wait for 1 second, and check if the SystemUI has been alive and well since the start.
         SystemClock.sleep(AFTER_TEXT_PROCESS_CHECK_DELAY)

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/EnterSplitScreenTest.kt

@@ -60,8 +60,8 @@ class EnterSplitScreenTest(
             }
             teardown {
                 eachRun {
-                    splitScreenApp.forceStop()
-                    secondaryApp.forceStop()
+                    splitScreenApp.exit()
+                    secondaryApp.exit()
                 }
             }
             assertions {

libs/WindowManager/Shell/tests/flicker/src/com/android/wm/shell/flicker/splitscreen/ExitSplitScreenTest.kt

@@ -65,8 +65,8 @@ class ExitSplitScreenTest(
             }
             teardown {
                 eachRun {
-                    splitScreenApp.forceStop()!!
-                    secondaryApp.forceStop()!!
+                    splitScreenApp.exit()
+                    secondaryApp.exit()
                 }
             }
         }

tests/FlickerTests/AndroidManifest.xml

@@ -27,6 +27,8 @@
     <uses-permission android:name="android.permission.ACCESS_SURFACE_FLINGER" />
     <!-- Enable / Disable tracing !-->
     <uses-permission android:name="android.permission.DUMP" />
+    <!-- Force-stop test apps -->
+    <uses-permission android:name="android.permission.FORCE_STOP_PACKAGES"/>
     <!-- Run layers trace -->
     <uses-permission android:name="android.permission.HARDWARE_TEST"/>
     <!-- Workaround grant runtime permission exception from b/152733071 -->