Refactor BatteryOptimizeUtils from enum to @IntDef

Based on the Android API Council guideline, we should avoid using the
Enum structure to define the constant definition.
go/android-api-guidelines#avoid-enum

Bug: 197595292
Test: make SettingsRoboTests
Change-Id: I4b22f0abde7f4ce2c3a0b076db786e619783d93e
10 files changed