[travis-ci] Add configuration file
android: Fix GNU old-style struct field designator

This gives a warning on clang, that turns into an error due to -Werror.
attrib-server: Remove unnecessary fields from struct gatt_channel

These fields are only used internally by attrib_channel_attach(). The
"No GATT server found..." error message was also removed as it is also
displayed by find_gatt_server().
core: Fix associating a GAttrib to a device on incoming connections

If BlueZ is running as slave, incoming connections using ATT CID will
have a GAttrib created for them. But this GAttrib will not be assigned
to the underlying device (whose struct btd_device instance was created
in response to the Device Connected mgmt event).

This patch fixes this by assigning the GAttrib to the btd_device as soon
as a connection is first requested, which is done using attio callbacks.

Note that a new GAttrib reference is taken because attio callbacks "own"
device->attrib and thus need their own reference.
alert: Only remove attio callback after ATT request was sent

If there is a single registered attio callback, any pending ATT requests
will be dropped as soon as it is removed. This commit makes sure that
the request is sent before removing the callback.

Other places using attio callbacks may need fixing as well.
android: Use 16-bit UUID for SDP search

These UUIDs are assigned by BT-SIG and therefore there is no need to
use full 128-bit UUIDs. This also avoids unnecessary conversion from
string representation.
android/tester: Update SDP PDU after UUID change

Now it is expected to receive a 16-bit UUID for PNP_INFO.
android/hidhost: Trivial coding style fix

Fix two lines over 80 columns.
android/client: Fix set_info command

Although this command is not implemented by BlueZ, make sure it is
callable from haltest so at least the IPC can be tested.

Also memset() the hid_info parameter to not pass uninitialized data
around.
android: Add test-ipc to "make check"