SurfaceFlinger: more aggressive infrequent layer detection

Change the algorithm that chooses the refresh rate to treat layers as
infrequent unless proven otherwise. This change helps with multiple
switches during scenarios of blinking cursor where the detection of
infrequent layer is too long. The down side on this change is that
animations will be considered infrequent as well for the first few frames.
However the touch boost is a good mitigation of this.

Test: Typing in Messages and observe refresh rate
Test: Settings->About->up time and observe refresh rate
Bug: 155062712
Bug: 156654519
Change-Id: I317c69bd063df5d70f2d5705163cf61c1c9b1fff