changelog: prepare 1.5.2

gap: set min encryption key size during init, if supported

libusb, posix and windows ports: use '-' instead of ':' in btstack_BD_ADDR.tlv filename

gap: add gap_secure_connections_active() to query if BR/EDR Secure Connecions are possible

att_server: use uint8_t for status returns

hci: fix handling of HCI Connection Complete with error (regression introduced in v1.5.1)

avdtp: use BLUETOOTH_SERVICE_CLASS_AUDIO_SINK / SOURCE instead of BLUETOOTH_PROTOCOL_AVDTP in SDP queries

hci: fix le scan with filterlist

gap: gap_enable_link_watchdog() uses automatic flush timeout to disconnect if data cannot be sent

posix: fix RTS/CTS configuration by keeping local termios copy

chipset: use da145xx in folder/file/function names for these SoCs

changelog: implemented VCS 1.0

hfp: free HFP Connection object on SDP error / Service not found

hci: ENABLE_HCI_SERIALIZED_CONTROLLER_OPERATIONS serializes Inquiry, Remote Name Request and Create Connection operations

hfp_gsm_model: fix tracking for call dropped during outgoing ringing

gatt-service/aics: move all fields that need to be initialized by the application to aics_info_t

att_db: search included service within handle range

changelog: add extended advertising

gap: disable scanning, advertising, connection before updating random address

changelog: esp32 audio update

esp32: update sdkconfig for esp-idf v4.3, disable Bluedroid host stack

pbap_client: emit vCard entry data as PBAP_DATA_PACKET

pbap_client: use SRM only if GOEP v2.0 or higher connection

goep_client: add goep_client_version_20_or_higher

l2cap: limit remote MTU by local tx configuration in ERTM