Update the Smartspace UI templates APIs.

- Add the 3rd-line data in BaseTemplateData to support new Android T
  use case;
- Remove the optional constructor from Text for API review comments in
  b/218860086;
- Add SubItemLoggingInfo to support the sub-card logging on the base
  card.

Fixes: 218860086
Test: atest CtsSmartspaceServiceTestCases
Change-Id: I39d7014f4f5b36719f54e191ed5af1fa45429a53