Set contentDescription on caret

Change-Id: I1f66b96b3f94649d85857b0107144bb4070ef448

src/com/android/launcher3/pageindicators/PageIndicatorLineCaret.java

@@ -158,6 +158,11 @@ public class PageIndicatorLineCaret extends PageIndicator {
                 mLinePaint);
     }
 
+    @Override
+    public void setContentDescription(CharSequence contentDescription) {
+        mAllAppsHandle.setContentDescription(contentDescription);
+    }
+
     @Override
     public void setScroll(int currentScroll, int totalScroll) {
         if (getAlpha() == 0) {