Report High usage even in a short period

In detector, we should also catch the following case:
1. Battery draining more than 25% even though usage time is less than
2 hours.

This cl stores the first time battery level, even though usage time
may be short.

Bug: 73012441
Test: RunSettingsRoboTests
Change-Id: I7106f7203718bfe2afe9cce297ea01b8fcf0be2d