Fix GATT Server disconnecting for no reason

When two devices are bonded, even if the device is supposed to act just
as a GATT Server, service discovery is performed. Doing "read by type"
should not trigger connection timeout, or disconnection, as the server
should wait for the client to finish connection.

Please note that it does not GATT Client behaviour, as they manage the
connection timeout through L2CA_SendFixedChnlData called on each data
packet.

Bug: 34951749
Test: manual
Change-Id: If53cf63dc204238a60839497992c870b1b39aa60