Add timezone to devcontainer

This fixes incorrect times in the logger output.

.devcontainer/devcontainer.json

@@ -10,6 +10,7 @@
         "notskm.clang-tidy",
         "streetsidesoftware.code-spell-checker"
     ],
+    "containerEnv": {"TZ": "${localEnv:TZ:Europe/Berlin}"},
     "runArgs": ["--gpus","all",                     // remove this line in case you have no gpus available
                 "--hostname=${localEnv:HOSTNAME}"], // HOSTNAME needs to be known by the vscode environment. It is probably necessary to add "export HOSTNAME=<hostname>" to the config file of your host machine's bash.
 

Containers/Ubuntu20_04.Dockerfile

@@ -18,6 +18,10 @@
 
 FROM nvidia/cuda:11.3.1-devel-ubuntu20.04
 
+# timezone
+ARG TZ
+ENV TZ="$TZ"
+
 ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update &&   \
     apt-get install -y  \