Integrating Android Keyboard Helper to surface commands to users.

Bug: 27527210
Change-Id: I97e6e42fe54e4195875581dcc04188f5552efd22
diff --git a/src/com/android/documentsui/MenuManager.java b/src/com/android/documentsui/MenuManager.java
index c6e9514..12c6217 100644
--- a/src/com/android/documentsui/MenuManager.java
+++ b/src/com/android/documentsui/MenuManager.java
@@ -17,6 +17,7 @@
 package com.android.documentsui;
 
 import android.app.Fragment;
+import android.view.KeyboardShortcutGroup;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -27,10 +28,14 @@
 import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.base.Shared;
 import com.android.documentsui.base.State;
+import com.android.documentsui.dirlist.ActionModeController;
 import com.android.documentsui.dirlist.DirectoryFragment;
 import com.android.documentsui.sidebar.RootsFragment;
 import com.android.internal.annotations.VisibleForTesting;
 
+import java.util.List;
+import java.util.function.IntFunction;
+
 public abstract class MenuManager {
 
     final protected SearchViewManager mSearchManager;