am ee1a3f16: Merge "Fix for setting Toolbar content descriptions" into lmp-preview-dev

* commit 'ee1a3f1612cb69fe5567bf7cde2496a4774ab8ed':
  Fix for setting Toolbar content descriptions
diff --git a/core/java/android/widget/Toolbar.java b/core/java/android/widget/Toolbar.java
index 8c67bb7..5033bee 100644
--- a/core/java/android/widget/Toolbar.java
+++ b/core/java/android/widget/Toolbar.java
@@ -592,7 +592,7 @@
      */
     public void setNavigationContentDescription(int resId) {
         ensureNavButtonView();
-        mNavButtonView.setContentDescription(getContext().getText(resId));
+        mNavButtonView.setContentDescription(resId != 0 ? getContext().getText(resId) : null);
     }
 
     /**