Use enhanced estimate battery info when available

This CL updates the battery page to get the updated strings and
other relevant battery info from directly from SettingsLib by
providing it an overrided drain time instead of manually changing
the value in the returned info. This will provide the added benefit
of using the new strings when appropriate that tell the user that
the estimate provided is based on their usage.

Test: robotests
Bug: 38399659
Change-Id: I0db572c2ea78910756314b6bf066d37e9f90a15c