Re-enable date-time once supported by kotlin

[Archdoog]

OpenAPITools/openapi-generator#1271

Platform class java.time.OffsetDateTime requires explicit JsonAdapter to be registered
for class java.time.OffsetDateTime dataVersion
for class com.osrm.api.models.RouteResponse
java.lang.IllegalArgumentException: Platform class java.time.OffsetDateTime requires explicit JsonAdapter to be registered
for class java.time.OffsetDateTime dataVersion
for class com.osrm.api.models.RouteResponse

https://github.com/ttnmapper/ttnmapper-android-v3/blob/master/app/src/main/java/org/ttnmapper/phonesurveyor/model/ttnV3/OffsetDateTimeAdapter.kt