[SB Refactor] Move InstantTaskExecutorRule to its own file so it can be

used by other tests.

Any tests that are exercising the `view.repeatWhenAttached` method need
to use this rule; otherwise, we'll get `IllegalStateException: should
be called from the main thread.` error. Moving the rule to its own file
lets us better import it for other tests.

Test: atest RepeatWhenAttachedTest
Bug: 238425913
Change-Id: Icab6b63b419a3898a8be35f16c06a8a3d09db4e2

packages/SystemUI/tests/src/com/android/systemui/lifecycle/InstantTaskExecutorRule.kt

@@ -0,0 +1,57 @@
+/*
+ *  Copyright (C) 2022 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.
+ *
+ */
+
+package com.android.systemui.lifecycle
+
+import androidx.arch.core.executor.ArchTaskExecutor
+import androidx.arch.core.executor.TaskExecutor
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+/**
+ * Test rule that makes ArchTaskExecutor main thread assertions pass. There is one such assert
+ * in LifecycleRegistry.
+ */
+class InstantTaskExecutorRule : TestWatcher() {
+    // TODO(b/240620122): This is a copy of
+    //  androidx/arch/core/executor/testing/InstantTaskExecutorRule which should be replaced
+    //  with a dependency on the real library once b/ is cleared.
+    override fun starting(description: Description) {
+        super.starting(description)
+        ArchTaskExecutor.getInstance()
+            .setDelegate(
+                object : TaskExecutor() {
+                    override fun executeOnDiskIO(runnable: Runnable) {
+                        runnable.run()
+                    }
+
+                    override fun postToMainThread(runnable: Runnable) {
+                        runnable.run()
+                    }
+
+                    override fun isMainThread(): Boolean {
+                        return true
+                    }
+                }
+            )
+    }
+
+    override fun finished(description: Description) {
+        super.finished(description)
+        ArchTaskExecutor.getInstance().setDelegate(null)
+    }
+}

packages/SystemUI/tests/src/com/android/systemui/lifecycle/RepeatWhenAttachedTest.kt

@@ -20,8 +20,6 @@ package com.android.systemui.lifecycle
 import android.testing.TestableLooper.RunWithLooper
 import android.view.View
 import android.view.ViewTreeObserver
-import androidx.arch.core.executor.ArchTaskExecutor
-import androidx.arch.core.executor.TaskExecutor
 import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.LifecycleOwner
 import androidx.test.filters.SmallTest
@@ -35,8 +33,6 @@ import kotlinx.coroutines.test.runBlockingTest
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
-import org.junit.rules.TestWatcher
-import org.junit.runner.Description
 import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
 import org.mockito.Mock
@@ -282,38 +278,4 @@ class RepeatWhenAttachedTest : SysuiTestCase() {
             _invocations.add(Invocation(lifecycleOwner))
         }
     }
-
-    /**
-     * Test rule that makes ArchTaskExecutor main thread assertions pass. There is one such assert
-     * in LifecycleRegistry.
-     */
-    class InstantTaskExecutorRule : TestWatcher() {
-        // TODO(b/240620122): This is a copy of
-        //  androidx/arch/core/executor/testing/InstantTaskExecutorRule which should be replaced
-        //  with a dependency on the real library once b/ is cleared.
-        override fun starting(description: Description) {
-            super.starting(description)
-            ArchTaskExecutor.getInstance()
-                .setDelegate(
-                    object : TaskExecutor() {
-                        override fun executeOnDiskIO(runnable: Runnable) {
-                            runnable.run()
-                        }
-
-                        override fun postToMainThread(runnable: Runnable) {
-                            runnable.run()
-                        }
-
-                        override fun isMainThread(): Boolean {
-                            return true
-                        }
-                    }
-                )
-        }
-
-        override fun finished(description: Description) {
-            super.finished(description)
-            ArchTaskExecutor.getInstance().setDelegate(null)
-        }
-    }
 }