Tighten the scope of ACTION_UDFPS_ILLUMINATE

This metric is not supposed to reflect the latency outside of the
illumination path, such as the time it takes the user to move their
finger to the trigger point on the sensor.

Bug: 221125251
Test: N/A
Change-Id: I47ea062a0527aed774ad5bd5e778a1def7f94601
1 file changed