Add a test AccessibilityService for A11Y IME API

This CL introduces a sample AccessibilityService that demonstrates how
to use newly added APIs based on IME APIs [1].

 [1]: Ia651a811093a939d00c081be1961e24ed3ad0356
      fb17e5ae7a9e1a095d114d8dde76f14578b6c233

Fix: 223671031
Test: Manually done as follows.
 1. make -j SampleInputMethodAccessibilityService
 2. adb install -r $OUT/system/app/SampleInputMethodAccessibilityService/SampleInputMethodAccessibilityService.apk
 3. adb shell settings put secure enabled_accessibility_services com.example.android.sampleinputmethodaccessibilityservice/com.example.android.sampleinputmethodaccessibilityservice.SampleInputMethodAccessibilityService
Change-Id: Iea75f4378118fadc142c56aad7667784111033ba

samples/SampleInputMethodAccessibilityService/Android.bp

@@ -0,0 +1,31 @@
+//
+// 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 {
+    default_applicable_licenses: ["Android-Apache-2.0"],
+}
+
+android_app {
+    name: "SampleInputMethodAccessibilityService",
+    min_sdk_version: "33",
+    target_sdk_version: "33",
+    sdk_version: "current",
+    srcs: ["src/**/*.java"],
+    resource_dirs: ["res"],
+    static_libs: [
+        "androidx.annotation_annotation",
+    ],
+}