Fix b/6575950 make shader program to support different precisions.

1. In shade code of Vignette and Fisheye, change from
   pixel coordinates to texture coordinates to avoid overflow.

2. Fix bug in ColorTemperature shader code

3. Revise shader code pseudo random number generator (used by
   BlackWhite, Grain, Lomo, Documentary filters) to ensure
   it produces no artifacts among devices with different precisions.

Change-Id: Ifb67f12f114bc9cd7fbfa74f7782f130c5244e5d