Fix the BLE connection failure with some mice

If enable the "connection parameters update" during GATT discovery,
it may cause some device connection failure due to connection timeout.
Since the the "connection parameter update" is enabled again when GATT
discovery completed, remove the enable of "connection parameter update"
after SMP complete to fix the issue.

This issue was already fixed in commit 2d41fe1, but then it was
re-introduced in commit 444a8da, which also removed comment explaining
the issue, added back in this patch.

Bug: 29060797
Change-Id: I42b0b36056821c30d887484e22bfcbd04ea7ca03
(cherry picked from commit 1ec17e0)

stack/smp/smp_act.c

@@ -1502,8 +1502,6 @@ void smp_pairing_cmpl(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
 {
     if (p_cb->total_tx_unacked == 0)
     {
-        /* update connection parameter to remote preferred */
-        L2CA_EnableUpdateBleConnParams(p_cb->pairing_bda, TRUE);
         /* process the pairing complete */
         smp_proc_pairing_cmpl(p_cb);
     }
@@ -1542,8 +1540,11 @@ void smp_idle_terminate(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
 *******************************************************************************/
 void smp_fast_conn_param(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
 {
-    /* disable connection parameter update */
-    L2CA_EnableUpdateBleConnParams(p_cb->pairing_bda, FALSE);
+    /* Disable L2CAP connection parameter updates while bonding since
+       some peripherals are not able to revert to fast connection parameters
+       during the start of service discovery. Connection paramter updates
+       get enabled again once service discovery completes. */
+    L2CA_EnableUpdateBleConnParams(p_cb->pairing_bda, false);
 }
 
 /*******************************************************************************