[hana] Update `$BLDR_CONTEXT` to `$PLAN_CONTEXT`.
[hana] Update `$BLDR_CONTEXT` to `$PLAN_CONTEXT`.

This was missed when updating variables in #120.

habitat-sh/habitat,nathenharvey/habitat,georgemarshall/habitat,georgemarshall/habitat,rsertelon/habitat,rsertelon/habitat,nathenharvey/habitat,nathenharvey/habitat,nathenharvey/habitat,georgemarshall/habitat,habitat-sh/habitat,rsertelon/habitat,habitat-sh/habitat,georgemarshall/habitat,georgemarshall/habitat,nathenharvey/habitat,rsertelon/habitat,habitat-sh/habitat,habitat-sh/habitat,georgemarshall/habitat,rsertelon/habitat,georgemarshall/habitat,nathenharvey/habitat,habitat-sh/habitat,habitat-sh/habitat,habitat-sh/habitat,rsertelon/habitat,georgemarshall/habitat,rsertelon/habitat