Constant Cleanup: Remove BT_TRACE_VERBOSE

BT_TRACE_VERBOSE turned on constants-as-strings in
logs in many parts of the stack, which is preferable
to obscure numbers.

Test: m -j37, check logspam is not worse than normal on a device
Change-Id: I1d24f1c1337290a8a2bcd9a0d937c9e0f1f1c611