floss: Remove the HF indicator support

Remove it from the HF feature flag to correct our current feature
capability, otherwise, this may cause HF trying to query AG's HF
capability and cause unexpected warning.
The feature should be safe to remove for now as it is optional.

Bug: 246003679
Tag: #floss
Test: Deploy and verify HFP works
Change-Id: Ib6db5f8416a41eb16865fc8a5f67a99ec5a6ad27