[bt][hfp] Fix AT Command matcher for Indicators Activation procedure

Bug: 74303
Test: fx test bt-hfp-audio-gateway-tests
Change-Id: Id1d06bfb9090cebda07b0f96e2f40a7e875c6cf1
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/514324
Reviewed-by: Jeff Belgum <belgum@google.com>
Commit-Queue: Jeff Belgum <belgum@google.com>
Commit-Queue: Ani Ramakrishnan <aniramakri@google.com>
Fuchsia-Auto-Submit: Ani Ramakrishnan <aniramakri@google.com>
diff --git a/src/connectivity/bluetooth/profiles/bt-hfp-audio-gateway/src/procedure.rs b/src/connectivity/bluetooth/profiles/bt-hfp-audio-gateway/src/procedure.rs
index 2742f45..c23da1d 100644
--- a/src/connectivity/bluetooth/profiles/bt-hfp-audio-gateway/src/procedure.rs
+++ b/src/connectivity/bluetooth/profiles/bt-hfp-audio-gateway/src/procedure.rs
@@ -233,6 +233,7 @@
             at::Command::Answer { .. } => Ok(Self::Answer),
             at::Command::Chup { .. } => Ok(Self::HangUp),
             at::Command::Biev { .. } => Ok(Self::TransferHfIndicator),
+            at::Command::Bia { .. } => Ok(Self::Indicators),
             _ => Err(ProcedureError::NotImplemented),
         }
     }