Universal: Set LANG="C.UTF-8" as ENV (devcontainers#417)

Author: samruddhikhandale

src/universal/.devcontainer/Dockerfile

@@ -11,9 +11,10 @@ RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
     # Restore man command
     && yes | unminimize 2>&1 
 
+ENV LANG="C.UTF-8"
+
 # Install basic build tools
-RUN LANG="C.UTF-8" \
-    && apt-get update \
+RUN apt-get update \
     && apt-get upgrade -y \
     && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
         make \