audio/player: Fix using invalid end index

When the End index is not set in ListItems the code automatically pick
the number of items as end index but the start index start with 0 so
the correct is to use number of items - 1.
audio/AVRCP: Fix using the wrong octet for folder type

Folder type is the 9 octet not the 10.
audio/AVRCP: Fix not setting playable flag for folder

When listing items some folders may be set as playable but the code was
ignoring it making it impossible to play any folder.
android/hal-audio: Check calloc return value

calloc() might return NULL and is usually checked for NULL in BlueZ.
android/hal-audio: Do not allocate memory if fd < 0

Fixes memory leak when returning bad fd we still allocate memory which
is not freed in the caller function audio_open_output_stream().
android/hal-audio: Fix memory leak

Free preset if set_blocking() fails.
android/hal-audio: Fix style issues
avrcp: Fix printing incorrect order for avrcp control header
avrcp: Fix printing order for browsing avrcp header
android/avrcp: Close AVRCP channel on error

This fixes resource leak.
gitignore: Add unit/avctp to .gitignore
tools/smp-tester: Fix expected key distribution to match latest bluetooth-next
emulator: Add HCI_Write_SSP_Debug_Mode support
emulator: Fix correct link key type generation
doc: Add experimental GATT API

This patch proposes an unified GATT API for local and remote services.
gatt: Add stub for gatt.{c, h} files

These files implement functions to handle ATT transactions, and expose
functions to allow other entities to manage GATT based services. It
is a replacement for src/attrib-server.c.
gatt: Register Manager D-Bus Interface

This patch registers GATT Service Manager D-Bus Interface. This
interface implements the methods to allow external application register
and unregister GATT Services.
gatt: Add registering external service

This patch allows external applications register a given service on
Bluez. Applications must provide an object path and a dictionary of
options. Options dictionary will be used later to provide additional
service information.
lib: Move GATT UUID to uuid.h

This patch moves GATT UUIDs definitions to a common header. uuid.h contains
helper functions to manipulate Bluetooth UUIDs and some common BR/EDR services
UUIDs.
gatt: Add helper for creating GATT services

This patch adds the btd_gatt_add_service() helper which adds a
GATT Service declaration to the local attribute database.