fix #2072: replace the call to getBestDateTimePattern
use the spinner date picker for API >= 21 (because the new mode doesn't fork correctly inside a ScrollView)
Merge pull request #2075 from wordpress-mobile/issue/2072-alternative-to-getBestDateTimePattern

fix #2072 alternative to get best date time pattern
Use a circular shape drawable as the background of the moderating progress view.

Fixes #2078
Merge pull request #2079 from wordpress-mobile/issue/2078-notifications-rounded-progress

Use a circular shape drawable as the background of the moderating progress view
Merge branch 'release/3.5' into develop