storaged: fix check_time logic

Skips event time check if failed to get start time.
Use ratelimited logging when gettime fails.

Test: adb shell setprop ro.storaged.event.perf_check 10000
Bug: 34630954
Bug: 34198239
Change-Id: I168ef3b4e4ed27257ec76373219c6214a7b7b2ed