Add accuracy and lastReadingTime to viv.geo

GPS functionality in phones often have values for when the last time the lat/long coordinate was read and the accuracy of the reading.

Here are some Android links:

• https://developer.android.com/reference/android/location/Location.html#getAccuracy()
• https://developer.android.com/reference/android/location/Location.html#getElapsedRealtimeNanos()

For Alexa, these values are surfaced as:

• timestamp
• coordinate.accuracyInMeters

https://developer.amazon.com/docs/custom-skills/location-services-for-alexa-skills.html#geolocation-interface