Move AppPreference to SettingsLib so other apps can use it.

Change-Id: I5240dcacdcd8b87a0965a0a9359cd7832b42e590
Fixes: 116364655
Test: robotests
diff --git a/packages/SettingsLib/AppPreference/Android.bp b/packages/SettingsLib/AppPreference/Android.bp
new file mode 100644
index 0000000..b56181d
--- /dev/null
+++ b/packages/SettingsLib/AppPreference/Android.bp
@@ -0,0 +1,13 @@
+android_library {
+    name: "SettingsLibAppPreference",
+
+    srcs: ["src/**/*.java"],
+    resource_dirs: ["res"],
+
+    libs: [
+        "androidx.annotation_annotation",
+        "androidx.preference_preference",
+    ],
+    sdk_version: "system_current",
+    min_sdk_version: "21",
+}