Add @IntRange annotation to clarify expected duration value

The setter and getter APIs for duration accept values
ranging from non-negative to positive-only. Add necessary
annotation to clarify the expected duration value.

Bug: 318430127
API-Coverage-Bug: 308666800
Test: atest FadeManagerConfigurationUnitTest
Change-Id: I201f96ac74169dc3f43d3a6c349bec99c9410d5f