Show "0" instead of "0 B" in storage settings.

Two benefits:
  - "0 B" might be a little confusing for sighted users
  - "zero bee" is definitely confusing for TalkBack users

Nonzero storage items will still read as "640 KB" which
should be enough for anyone.

Change-Id: I5c89f7c6382ca14fb91d7d1dd145977f855618ae
Fixes: 27973778

src/com/android/settings/deviceinfo/StorageItemPreference.java

@@ -38,7 +38,9 @@ public class StorageItemPreference extends Preference {
     }
 
     public void setStorageSize(long size, long total) {
-        setSummary(Formatter.formatFileSize(getContext(), size));
+        setSummary(size == 0
+                ? String.valueOf(0)
+                : Formatter.formatFileSize(getContext(), size));
         if (total == 0) {
             progress = 0;
         } else {