TaskStorage: Fix assertContainsExactly

Update private helper assertContainsExactly() to ensure that we
have exactly one element in the list and also make it generic so
that it can be used against any list, for example listWaiting()
or listRunning()

Change-Id: I93b9f220dd865decbf8fd18240e5a47fb2042115
1 file changed
tree: b8a852aaf557f0ea41b5cf4b327d0a4527c49a65
  1. .gitignore
  2. .mailmap
  3. .settings/
  4. BUILD
  6. src/