SurfaceFlinger: tune LayerHistory to be less aggressive

Increase the thresholds to mark layer as "relevant" to be less agressive
when changing refresh rate based on content.

Bug: 136558136
Test: 1) put icons in drawer/folder on homescreen
2) tap drawer to expand
3) tap homescreen to contract drawer
4) goto 2), repeating quickly.
Test: libsurfaceflinger_unnittest

Change-Id: I2a9b696f267d93720408a41dceb4acb7dc80bd69