Change registerUsageSessionObserver to take Duration for timelimits

Old version of the api will be removed in a follow up CL

Fixes: 123939205
Test: atest android.app.usage.cts.UsageStatsTest#testObserveUsagePermissionForRegisterObserver
Test: atest com.android.cts.devicepolicy.ProfileOwnerTest#testAppUsageObserver
Change-Id: I06340c13dd93a17c4480327fb9eff16575928c35