Merge changes Id47b288d,I969565eb,Iba2e654e

* changes:
  logd: drop can_read_security_logs
  logd: create FlushToState class
  logd: fix bug in FlushTo when requesting exact sequence number
tree: 1b83741d7331cbbcc01bb832554daf33c698e994
  1. liblog/
  2. logcat/
  3. logd/
  4. logwrapper/