hearing_aid: Always update conn params on connect

Connection parameters update does not change the anchor point
so we don't need to update connections parameters on one
connection at a time.

All the usage of connection_update_status will be cleaned in a
follow-up to minimize modifications for this release.

This is done to mitigate a bug on Broadcom controllers where with the
previous behavior the LE Connection Update Complete event was sometime
not sent on the second HA leading to a Disconnection.

Bug: 313466876
Test: manual, on a Pixel 6a and Pixel 7a, stream to a ASHA device
Change-Id: I26337437f3d994c2944981afd27cb1a95943be88