has_client: Improve subscribtion to control point

As per specification we should register for notification when EATT is
used and indication if EATT is NOT used. This is bit odd as having
support and being able to connect, and maintaing connection are
different things.
To be on the save side we would like to register to both - notification
and indication and let server to decide what it is sent (based on the
bearer).

With this patch, we register to anything what servers allow dispite
EATT tracking.

This will also help PTS testing

Bug: 238171211
Test: atest BluetoothInstrumentationTests
Test: PTS
Tag: #feature
Merged-In: I7c30278de00e3e75c6ecd9b6c55258b7eef92fe9
Change-Id: I7c30278de00e3e75c6ecd9b6c55258b7eef92fe9
(cherry picked from commit 967aa140)