kvdbd is single threaded.
If CP calls property_list, AP'S kvdbd will continue to send to cp,
then accept will not be executed.
If another thread at CP loops to call property_set,
the AP server-side's pending queue will be full and reject next connection.
Bluetooth now loops through 15 times to call 'property_set',
So to avoid rejecting the connection,
set a macro to separately manage the listening count of kvdb
Signed-off-by: yintao <yintao@xiaomi.com>
6b596e4ff5