[Ovmsdev] Android client crashes

[Tom Parker]

I found a couple of new android client crashes.

One was caused by the TPMS message which I've sent a pull request to fix.

The other crash is in the GPS message. The v2 car module's car_drivemode 
is a hex encoded char. In v3 this has turned into a string which 
defaults to 'standard'. The android client crashes on receipt of this 
message. I'm not sure how to fix this, the field is only used by the 
twizzy (as a bit field) and I'm not sure the intention of the 
ms_v_env_drivemode string metric is.

In the meantime this patch avoids the crash

diff --git 
a/vehicle/OVMS.V3/components/ovms_server_v2/src/ovms_server_v2.cpp 
b/vehicle/OVMS.V3/components/ovms_server_v2/src/ovms_server_v2.cpp
index 9d3a6ad..eddb89f 100644
--- a/vehicle/OVMS.V3/components/ovms_server_v2/src/ovms_server_v2.cpp
+++ b/vehicle/OVMS.V3/components/ovms_server_v2/src/ovms_server_v2.cpp
@@ -558,7 +558,7 @@ void OvmsServerV2::TransmitMsgGPS(bool always)
    else
buffer.append(StandardMetrics.ms_v_pos_speed->AsString("0",Mph).c_str());
    buffer.append(",");
- 
buffer.append(StandardMetrics.ms_v_env_drivemode->AsString("standard").c_str());
+  buffer.append("0"); // car_drivemode
    buffer.append(",");
buffer.append(StandardMetrics.ms_v_bat_power->AsString("0",Other,1).c_str());
    buffer.append(",");