Reducing the click delay while screen magnification is enabled.

1. If screen magnification is enabled the user has to triple tap
   and lift or triple tap and hold to engage magnification. Hence,
   we delay the touch events until we are sure that it is no longer
   possible for the user to perform a multi-tap to engage
   magnification. While such a delay is unavoidable it feels a
   bit longer than it should be. This change reduces the delay
   between taps to be considered a multi-tap, essentially making
   the click delay shorter.

bug:7139918

Change-Id: I2100945171fff99600766193f0effdaef1f1db8f