nimble/audio/bass: Add data length check in BASS remote scan

This commit adds data length checks to remote scan operations.
Now any data coming with remote scan start/stop will result
in instant ATT error.

nimble/host/audio/services/bass/src/ble_audio_svc_bass.c

@@ -251,6 +251,10 @@ ble_svc_audio_bass_receive_state_free(struct ble_svc_audio_bass_rcv_state_entry
 static int
 ble_svc_audio_bass_remote_scan_stopped(uint8_t *data, uint16_t data_len, uint16_t conn_handle)
 {
+    if (data_len > 1) {
+        return BLE_ATT_ERR_WRITE_REQ_REJECTED;
+    }
+
     struct ble_audio_event ev = {
         .type = BLE_AUDIO_EVENT_BASS_REMOTE_SCAN_STOPPED
     };
@@ -264,6 +268,10 @@ ble_svc_audio_bass_remote_scan_stopped(uint8_t *data, uint16_t data_len, uint16_
 static int
 ble_svc_audio_bass_remote_scan_started(uint8_t *data, uint16_t data_len, uint16_t conn_handle)
 {
+    if (data_len > 1) {
+        return BLE_ATT_ERR_WRITE_REQ_REJECTED;
+    }
+
     struct ble_audio_event ev = {
         .type = BLE_AUDIO_EVENT_BASS_REMOTE_SCAN_STARTED
     };