Modify touchpad ballistic curves based on the UX study results.

We ran the second trackpad ballistic user study to test different designs
of the three ballistic phases. The results suggest a later start of the
acceleration phase. The curves and sensitivities are updated accordingly.

Bug: 288354054
Bug: 289270505
Test: manually
Change-Id: I2012302be44c0ad191951b6950140070cd20a2fb