AP_Vehicle: explicitly number ModeReason enumeration values

These are logged, and mapping back is much easier if you have this
numbering

libraries/AP_Vehicle/ModeReason.h

@@ -17,49 +17,49 @@
 
 // interface to set the vehicles mode
 enum class ModeReason : uint8_t {
-  UNKNOWN,
-  RC_COMMAND,
-  GCS_COMMAND,
-  RADIO_FAILSAFE,
-  BATTERY_FAILSAFE,
-  GCS_FAILSAFE,
-  EKF_FAILSAFE,
-  GPS_GLITCH,
-  MISSION_END,
-  THROTTLE_LAND_ESCAPE,
-  FENCE_BREACHED,
-  TERRAIN_FAILSAFE,
-  BRAKE_TIMEOUT,
-  FLIP_COMPLETE,
-  AVOIDANCE,
-  AVOIDANCE_RECOVERY,
-  THROW_COMPLETE,
-  TERMINATE,
-  TOY_MODE,
-  CRASH_FAILSAFE,
-  SOARING_FBW_B_WITH_MOTOR_RUNNING,
-  SOARING_THERMAL_DETECTED,
-  SOARING_THERMAL_ESTIMATE_DETERIORATED,
-  VTOL_FAILED_TRANSITION,
-  VTOL_FAILED_TAKEOFF,
-  FAILSAFE, // general failsafes, prefer specific failsafes over this as much as possible
-  INITIALISED,
-  SURFACE_COMPLETE,
-  BAD_DEPTH,
-  LEAK_FAILSAFE,
-  SERVOTEST,
-  STARTUP,
-  SCRIPTING,
-  UNAVAILABLE,
-  AUTOROTATION_START,
-  AUTOROTATION_BAILOUT,
-  SOARING_ALT_TOO_HIGH,
-  SOARING_ALT_TOO_LOW,
-  SOARING_DRIFT_EXCEEDED,
-  RTL_COMPLETE_SWITCHING_TO_VTOL_LAND_RTL,
-  RTL_COMPLETE_SWITCHING_TO_FIXEDWING_AUTOLAND,
-  MISSION_CMD,
-  FRSKY_COMMAND,
-  FENCE_RETURN_PREVIOUS_MODE,
-  QRTL_INSTEAD_OF_RTL
+  UNKNOWN = 0,
+  RC_COMMAND = 1,
+  GCS_COMMAND = 2,
+  RADIO_FAILSAFE = 3,
+  BATTERY_FAILSAFE = 4,
+  GCS_FAILSAFE = 5,
+  EKF_FAILSAFE = 6,
+  GPS_GLITCH = 7,
+  MISSION_END = 8,
+  THROTTLE_LAND_ESCAPE = 9,
+  FENCE_BREACHED = 10,
+  TERRAIN_FAILSAFE = 11,
+  BRAKE_TIMEOUT = 12,
+  FLIP_COMPLETE = 13,
+  AVOIDANCE = 14,
+  AVOIDANCE_RECOVERY = 15,
+  THROW_COMPLETE = 16,
+  TERMINATE = 17,
+  TOY_MODE = 18,
+  CRASH_FAILSAFE = 19,
+  SOARING_FBW_B_WITH_MOTOR_RUNNING = 20,
+  SOARING_THERMAL_DETECTED = 21,
+  SOARING_THERMAL_ESTIMATE_DETERIORATED = 22,
+  VTOL_FAILED_TRANSITION = 23,
+  VTOL_FAILED_TAKEOFF = 24,
+  FAILSAFE = 25, // general failsafes, prefer specific failsafes over this as much as possible
+  INITIALISED = 26,
+  SURFACE_COMPLETE = 27,
+  BAD_DEPTH = 28,
+  LEAK_FAILSAFE = 29,
+  SERVOTEST = 30,
+  STARTUP = 31,
+  SCRIPTING = 32,
+  UNAVAILABLE = 33,
+  AUTOROTATION_START = 34,
+  AUTOROTATION_BAILOUT = 35,
+  SOARING_ALT_TOO_HIGH = 36,
+  SOARING_ALT_TOO_LOW = 37,
+  SOARING_DRIFT_EXCEEDED = 38,
+  RTL_COMPLETE_SWITCHING_TO_VTOL_LAND_RTL = 39,
+  RTL_COMPLETE_SWITCHING_TO_FIXEDWING_AUTOLAND = 40,
+  MISSION_CMD = 41,
+  FRSKY_COMMAND = 42,
+  FENCE_RETURN_PREVIOUS_MODE = 43,
+  QRTL_INSTEAD_OF_RTL = 44,
 };