change(ble): Change requested connection interval range to 30-40 ms

This speeds up file transfers from Linux machines. Looks like the impact
on power consumption is not too large. Android also does not seem to
take this into account.

epicardium/ble/ble_main.c

@@ -98,8 +98,9 @@ static const appUpdateCfg_t bleUpdateCfg =
 {
   6000,                                   /*! Connection idle period in ms before attempting
                                               connection parameter update; set to zero to disable */
-  800/1.25,                               /*! Minimum connection interval in 1.25ms units */
-  1000/1.25,                              /*! Maximum connection interval in 1.25ms units */
+  30/1.25,                                 /*! Minimum connection interval in 1.25ms units.
+                                              Values < 8 didn't work with my Tinkpad T470 */
+  40/1.25,                                /*! Maximum connection interval in 1.25ms units */
   0,                                      /*! Connection latency */
   9000/10,                                /*! Supervision timeout in 10ms units */
   5                                       /*! Number of update attempts before giving up */