More layoutlib tests.

- Add another layout including more widgets and thus testing layoutlib
  better.
- Update targetSdk Version to 22.
- Handling of dynamic ids (@+id/) in LayoutLibTestCallback is buggy.
  Since this is not a problem in Studio, and this is not testing the
  callback, work around the issue by declaring the ids in
  values/ids.xml.

Change-Id: I457c105e8556c4df13cd86da2250fe5fd37843a8