Move Slice code to spa/slice folder & add tests.

Bug: 244122804
Test: unit-test & local build gallery
Change-Id: I61baac3e52e1ac3d7b674bc8366bee0074586115
diff --git a/packages/SettingsLib/Spa/testutils/Android.bp b/packages/SettingsLib/Spa/testutils/Android.bp
index 0f618fa..48df569 100644
--- a/packages/SettingsLib/Spa/testutils/Android.bp
+++ b/packages/SettingsLib/Spa/testutils/Android.bp
@@ -24,6 +24,7 @@
     srcs: ["src/**/*.kt"],
 
     static_libs: [
+        "androidx.arch.core_core-runtime",
         "androidx.compose.ui_ui-test-junit4",
         "androidx.compose.ui_ui-test-manifest",
         "mockito",
diff --git a/packages/SettingsLib/Spa/testutils/build.gradle b/packages/SettingsLib/Spa/testutils/build.gradle
index 58b4d42..be8df43 100644
--- a/packages/SettingsLib/Spa/testutils/build.gradle
+++ b/packages/SettingsLib/Spa/testutils/build.gradle
@@ -47,6 +47,7 @@
 }
 
 dependencies {
+    api "androidx.arch.core:core-runtime:2.1.0"
     api "androidx.compose.ui:ui-test-junit4:$jetpack_compose_version"
     api "com.google.truth:truth:1.1.3"
     api "org.mockito:mockito-core:2.21.0"
diff --git a/packages/SettingsLib/Spa/testutils/src/com/android/settingslib/spa/testutils/InstantTaskExecutorRule.kt b/packages/SettingsLib/Spa/testutils/src/com/android/settingslib/spa/testutils/InstantTaskExecutorRule.kt
new file mode 100644
index 0000000..43c18d4
--- /dev/null
+++ b/packages/SettingsLib/Spa/testutils/src/com/android/settingslib/spa/testutils/InstantTaskExecutorRule.kt
@@ -0,0 +1,55 @@
+/*
+ *  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.settingslib.spa.testutils
+
+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.
+
+ * This is a copy of androidx/arch/core/executor/testing/InstantTaskExecutorRule which should be
+ * replaced once the dependency issue is solved.
+ */
+class InstantTaskExecutorRule : TestWatcher() {
+    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)
+    }
+}