Guard against null container in WidgetProvider

Should never happen in normal use cases, but was seeing NPEs
when testing on an emulator with an out-of-date version of Google
Play Services and the date set to the past.

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>
Support widget vertical resizing on large screen tablets

Signed-off-by: Greg Meiste <greg.meiste@gmail.com>