[#735] Enable META questions all survey groups

* The _META_ questions, were enabled only in _Monitoring_ groups
* On the v2.0 APK, if we don't have a "Display Name" for a data point,
  it shows "Unknown"
[#736] Release Notes v1.7.2.1
Merge branch 'release/1.7.2'
Merge branch 'master' into develop