Check packet length in bta_av_proc_meta_cmd

Bug: 111893951
Test: manual - connect A2DP
Change-Id: Ibbf347863dfd29ea3385312e9dde1082bc90d2f3
(cherry picked from commit ed51887f921263219bcd2fbf6650ead5ec8d334e)

void bta_av_api_disconnect(tBTA_AV_DATA* p_data) {
  AVDT_DisconnectReq(p_data->api_discnt.bd_addr, bta_av_conn_cback);
  alarm_cancel(bta_av_cb.link_signalling_timer);
}

void bta_av_api_disconnect(tBTA_AV_DATA* p_data) {
  AVDT_DisconnectReq(p_data->api_discnt.bd_addr, bta_av_conn_cback);
  alarm_cancel(bta_av_cb.link_signalling_timer);
}
