Add FirstScreenWidget plugin interface

Bug: 115877296
Change-Id: I974300a6460677758cbe99cab3bb71339eb2928b
diff --git a/src_plugins/com/android/systemui/plugins/FirstScreenWidget.java b/src_plugins/com/android/systemui/plugins/FirstScreenWidget.java
new file mode 100644
index 0000000..8d7dd4b
--- /dev/null
+++ b/src_plugins/com/android/systemui/plugins/FirstScreenWidget.java
@@ -0,0 +1,15 @@
+package com.android.systemui.plugins;
+
+import android.view.ViewGroup;
+import com.android.systemui.plugins.annotations.ProvidesInterface;
+
+/**
+ * Implement this interface to wrap the widget on the first home screen, e.g. to add new content.
+ */
+@ProvidesInterface(action = FirstScreenWidget.ACTION, version = FirstScreenWidget.VERSION)
+public interface FirstScreenWidget extends Plugin {
+    String ACTION = "com.android.systemui.action.PLUGIN_FIRST_SCREEN_WIDGET";
+    int VERSION = 1;
+
+    void onWidgetUpdated(ViewGroup widgetView);
+}