recovery: report compliant reboot reason

shutdown and reboot should have a corresponding sub-reason.

Adding:
    "reboot,fastboot_menu"
    "reboot,recovery_menu"
    "reboot,recovery_ui"
    "shutdown,fastboot"
    "shutdown,recovery"
    "reboot,unknown#"

Test: none
Change-Id: Icf1ab0d462ec2de2272914a36994a095998d6186
diff --git a/recovery.cpp b/recovery.cpp
index 20e5a1b..eb0c2b2 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -356,6 +356,8 @@
             : device->InvokeMenuItem(chosen_item);
 
     switch (chosen_action) {
+      case Device::REBOOT_FROM_FASTBOOT:    // Can not happen
+      case Device::SHUTDOWN_FROM_FASTBOOT:  // Can not happen
       case Device::NO_ACTION:
         break;