am 1bebdcb4: Move RingCharBuffer as a singleton in Util

Merge commit '1bebdcb4e422c0d9e52833dfd3bc0a8b9e07a266' into gingerbread-plus-aosp

* commit '1bebdcb4e422c0d9e52833dfd3bc0a8b9e07a266':
  Move RingCharBuffer as a singleton in Util