Update CTS CarWatchdogHostTest to verify recurring I/O overuse kill.

- Watchdog service performs I/O overuse kill/disable only on recurring
disk I/O overuse and after the display is turned off. Update the CTS
test to verify the app kill after these conditions are met.
- Update CarWatchdogHostTest to capture and verify the metrics uploaded
on exceeding disk I/O thresholds and on killing/disaling app on recurring
disk I/O overuse.
- Update device side app to delete files as soon as the write completes.
This helps to reclaim the storage space quickly. Otherwise, testing
recurring overuse might fill-up disk storage on low storage capacity
devices.

Test: run cts -m CtsCarHostTestCases -t \
android.car.cts.CarWatchdogHostTest
Fix: 204207264
Bug: 184310189
Fix: 197650622

Change-Id: If997498c7560eb6224c6b49db3263347bcaa40ac
2 files changed