Add ability to increase light idle time linearly.

Make it possible to increase the light idle time linearly instead of
exponentially.

Bug: 299329948
Test: atest DeviceIdleTest
Test: atest FrameworksMockingServicesTests:DeviceIdleControllerTest
Change-Id: I4e7c07fa1d2653446ae5617f11fbd26ec39438ab
4 files changed