Create a main switch preference widget.

Based on our ux spec, we create this widget to
let everyone can follow up our spec easily.

Bug: 175181773
Test: Run robotest and apply this widget in Settings and see the ui
Change-Id: I4ea5f38c44aacfeb2c8dbe4a7d31159712f95441
diff --git a/packages/SettingsLib/MainSwitchPreference/Android.bp b/packages/SettingsLib/MainSwitchPreference/Android.bp
new file mode 100644
index 0000000..1dc18f5
--- /dev/null
+++ b/packages/SettingsLib/MainSwitchPreference/Android.bp
@@ -0,0 +1,14 @@
+android_library {
+    name: "SettingsLibMainSwitchPreference",
+
+    srcs: ["src/**/*.java"],
+    resource_dirs: ["res"],
+
+    static_libs: [
+          "androidx.preference_preference",
+          "SettingsLibRestrictedLockUtils",
+    ],
+
+    sdk_version: "system_current",
+    min_sdk_version: "21",
+}