Announce content desc of workspace immediately after unlocking the lock screen.
b/22051420

Change-Id: I41ab93782383c04e0074d87632ebe8d884a8e208
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 77c4540..210366e 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -3519,6 +3519,8 @@
             text.add(getString(R.string.all_apps_button_label));
         } else if (mState == State.WIDGETS) {
             text.add(getString(R.string.widget_button_text));
+        } else if (mWorkspace != null) {
+            text.add(mWorkspace.getCurrentPageDescription());
         } else {
             text.add(getString(R.string.all_apps_home_button_label));
         }