Adding 'uhid' permission for bluetooth stack.

This CL is in support of another CL c/2048848, topic
'Refactor hid command in /frameworks/base/cmds'
in internal master. Adding the permissions for bluetooth
devices here to access uhid_node as part of the new 'uhid'
group.

Bug: 34052337
Test: Tested on angler, bluetooth mouse works OK.

Change-Id: I63963984a0a3dccb4fccc64bb6fef4e809e2737e