Update setNextPostDialWaitChar API

This CL does the following:
  - make the API public
  - rename it from setNextPostDialWaitChar to setNextPostDialChar
  - remove reference to "wait" from the API documentation

BUG: 19216940, 19216942
Change-Id: Ic4c7f44a900fd79875318d8c565c3aacaa42b962
2 files changed