Update #registerAppUsageLimitObserver to accept time remaining.

UsageStatsManager#registerAppUsageLimitObserver now accepts the time
remaining in addition to the total time limit.

The API now also uses java.time.Duration instead of long+TimeUnit for
the total time and remaining time.

Bug: 124272203
Test: atest FrameworksServicesTests:AppTimeLimitControllerTests
Test: atest android.app.usage.cts.UsageStatsTest#testObserveUsagePermissionForRegisterObserver
Test: atest android.app.usage.cts.UsageStatsTest#testObserveUsagePermissionForUnregisterObserver
Test: manual (mmma frameworks/base/tests/UsageStatsTest/)
Change-Id: I6f85ca9295cad46e10a30035b67e6210ae5c1886