Allow empty kernel wakelock names

The kernel wakelock api does not require the client to provide a name,
so we cannot enforce that the name is not the empty string.

Test: atest android.cts.statsd.atom.HostAtomTests#testKernelWakelock
Bug: 159673282
Change-Id: Icf979ebe2417fa682d59e802999dc60e85303281
1 file changed