Layoutlib tests now check methods return value [DO NOT MERGE]

The change is a cherry-pick of relevant fixes from the following
commits on master branch:
the followning commits:
9be03c4e980d3058aeb3fd730da5f7d4a4a4f8a8 and
e05bb956ce429618fd4f971a9dc708b9313c59ea

Change-Id: I87cef323c4eaee4e9f60475f01156b276593fa50
3 files changed