Fix accessibility description on master clear

Only include visible views

Change-Id: I271ae87c788e270b15e7ca8758059771cde16d33
Fixes: 28316423
diff --git a/src/com/android/settings/MasterClear.java b/src/com/android/settings/MasterClear.java
index 17d3572..540c93f 100644
--- a/src/com/android/settings/MasterClear.java
+++ b/src/com/android/settings/MasterClear.java
@@ -177,6 +177,9 @@
     }
 
     private void getContentDescription(View v, StringBuffer description) {
+       if (v.getVisibility() != View.VISIBLE) {
+           return;
+       }
        if (v instanceof ViewGroup) {
            ViewGroup vGroup = (ViewGroup) v;
            for (int i = 0; i < vGroup.getChildCount(); i++) {