Ble: set max connection interal same as min, kinda speedups everything

targets/f7/ble_glue/extra_beacon.c

@@ -9,7 +9,8 @@
 #define GAP_MS_TO_SCAN_INTERVAL(x) ((uint16_t)((x) / 0.625))
 
 // Also used as an indicator of whether the beacon had ever been configured
-#define GAP_MIN_ADV_INTERVAL_MS (20)
+// AN5289: 4.7, we need at least 25ms + advertisement, which is 30 ms
+#define GAP_MIN_ADV_INTERVAL_MS (30u)
 
 typedef struct {
     GapExtraBeaconConfig last_config;

targets/f7/ble_glue/profiles/serial_profile.c

@@ -46,8 +46,8 @@ static GapConfig serial_template_config = {
     .bonding_mode = true,
     .pairing_method = GapPairingPinCodeShow,
     .conn_param = {
-        .conn_int_min = 0x18, // 30 ms
-        .conn_int_max = 0x24, // 45 ms
+        .conn_int_min = 0x18, // AN5289: 4.7, we need at least 25ms + advertisement, which is 30 ms
+        .conn_int_max = 0x18, // 30 ms
         .slave_latency = 0,
         .supervisor_timeout = 0,
     }};