am 0e7235b0: b/2194249 Prevent Calendar from playing multiple notification tones around the same time. This is a safe but temp fix for overlapping ringtones playing at the same time.

Merge commit '0e7235b00fdf47c773592a324c4a62ef95d1dcf4' into eclair-mr2

* commit '0e7235b00fdf47c773592a324c4a62ef95d1dcf4':
  b/2194249 Prevent Calendar from playing multiple notification tones around the same time.