Reduce camera launch time by about 250ms.

This reduces the amount of time available to the user to cancel
launching the camera in order to improve average launch time.

It also increases the threshhold for flings and motions to prevent
unintentional launches which are costly in terms of falsing.

Fixes bug b/11657355

Change-Id: I852abbe3ce8ddddcb65f3a48a2f8111d20126189