floss: Add kBtSnoopLogModeKernel for btsnoop mode in kernel

Floss currently generates btsnoop logs in kernel space,
so Capture and DumpSnoozLogToFile are not required.

If we switch Floss to user space btsnoop logs,
we may need to update umask and output file path to
avoid permission errors.

Bug: 327542410
Tag: #floss
Test: btclient -c dumpsys
Test: m com.android.btservices
Flag: EXEMPT, floss only change

Change-Id: I887c033d20b31b15d93362be25e5c35e79c43eb1