AOSP/DeskClock - Clean up some TODOs and deprecated calls

Test: manual, tested the DeskClock UI. As well tests were ran as follows

$ source build/envsetup.sh
$ lunch aosp_sargo-userdebug
$ make DeskClock
$ adb install out/target/product/sargo/product/app/DeskClock/DeskClock.apk
$ atest DeskClockTests
$ make DeskClockJava
$ adb install out/target/product/sargo/product/app/DeskClockJava/DeskClockJava.apk
$ atest DeskClockTests

BUG: 157255731
Change-Id: I4fafbc1021102dc7da7ad592a8840a9220d320cd