AOSP/DeskClock - Add Kotlin files for Stopwatch data files

Test: manual - Ran the following on Sargo phone. Tested the stopwatch
interactions (ie. start, pause, reset, laps, share).

$ source build/envsetup.sh
$ lunch aosp_sargo-userdebug
$ make DeskClockKotlin -j
$ adb install out/target/product/sargo/product/app/DeskClockKotlin/DeskClockKotlin.apk

BUG: 157255731
Change-Id: Ia3ac367d2ba43fe0f08386a3f099878fd3af72d4
7 files changed