Add Filtering for snoop logs based on L2CAP and RFCOMM Channels (2/4)

Snoop logs will now always exist but will be filtered by default. If
full logging is turned on then al the packets will be logged.

Bug: 112970672
Bug: 67669544
Test: See that the snoop file always exists but is filtered when
snooplogs are disabled and unfiltered when enabled.

Change-Id: I542a5908fcd8bf17964f76509de5c8e1b9925f42