Add Filtering for snoop logs based on L2CAP and RFCOMM Channels (3/4)

* Change btsnoop logging into disabled, filtered, and full modes
* When ro.isdebuggable is 1, filtered logging is enabled by default
* Otherwise, disabled by default
* When legacy mode is enabled, translate it to full and reset legacy
  property to empty

Bug: 112970672
Bug: 67669544
Test: See that the snoop file always exists but is filtered when
snooplogs are disabled and unfiltered when enabled. Unit tests.
Change-Id: Icec8c4f2f01138b8858765f6f1c1318e1f005135