Remove concept of system bar from window manager.

It was already hardcoded to false, this change removes the dead code.

Change-Id: I5e543344e60f69cb9882a70ba29f7c09404ad9fc
diff --git a/tools/layoutlib/bridge/src/android/view/IWindowManagerImpl.java b/tools/layoutlib/bridge/src/android/view/IWindowManagerImpl.java
index a7b48bb..6343049 100644
--- a/tools/layoutlib/bridge/src/android/view/IWindowManagerImpl.java
+++ b/tools/layoutlib/bridge/src/android/view/IWindowManagerImpl.java
@@ -49,15 +49,13 @@
     private final Configuration mConfig;
     private final DisplayMetrics mMetrics;
     private final int mRotation;
-    private final boolean mHasSystemNavBar;
     private final boolean mHasNavigationBar;
 
     public IWindowManagerImpl(Configuration config, DisplayMetrics metrics, int rotation,
-            boolean hasSystemNavBar, boolean hasNavigationBar) {
+            boolean hasNavigationBar) {
         mConfig = config;
         mMetrics = metrics;
         mRotation = rotation;
-        mHasSystemNavBar = hasSystemNavBar;
         mHasNavigationBar = hasNavigationBar;
     }
 
@@ -79,11 +77,6 @@
         return mHasNavigationBar;
     }
 
-    @Override
-    public boolean hasSystemNavBar() throws RemoteException {
-        return mHasSystemNavBar;
-    }
-
     // ---- unused implementation of IWindowManager ----
 
     @Override