examples: Add Kconfig for resetting provisioning config

examples/provisioning/wifi_prov_mgr/main/Kconfig.projbuild

@@ -20,4 +20,11 @@ menu "Example Configuration"
         default 1 if EXAMPLE_PROV_TRANSPORT_BLE
         default 2 if EXAMPLE_PROV_TRANSPORT_SOFTAP
 
+    config EXAMPLE_RESET_PROVISIONED
+        bool
+        default n
+        prompt "Reset provisioned status of the device"
+        help
+            This erases the NVS to reset provisioned status of the device on every reboot.
+            Provisioned status is determined by the Wi-Fi STA configuration, saved on the NVS.
 endmenu

examples/provisioning/wifi_prov_mgr/main/app_main.c

@@ -185,9 +185,13 @@ void app_main(void)
     ESP_ERROR_CHECK(wifi_prov_mgr_init(config));
 
     bool provisioned = false;
+#ifdef CONFIG_EXAMPLE_RESET_PROVISIONED
+    wifi_prov_mgr_reset_provisioning();
+#else
     /* Let's find out if the device is provisioned */
     ESP_ERROR_CHECK(wifi_prov_mgr_is_provisioned(&provisioned));
 
+#endif
     /* If device is not yet provisioned start provisioning service */
     if (!provisioned) {
         ESP_LOGI(TAG, "Starting provisioning");