has_client.cc: Connect shall connect only requested device

`Connect` method should only connect single device, defined by
`address` parameter. Otherwise, fail on connection of other device in
group will lead to disconnection of already connected ones. Allow
Java layer to handle connecting all group members, as other profiles do.

Bug: 361014973
Flag: com.android.bluetooth.flags.hap_connect_only_requested_device
Test: atest --host --no-bazel-mode bluetooth_has_test
Change-Id: I26ebab5c6105c803865bdce49e008e9c997f3537