suite_scheduler: rubik builds bug fix

Suite Scheduler was not scheduling certain suites for certain builds
despite config/log messages looking reasonable. (example
GraphicsPerBuild for kevin-kernelnext: b/227351798).

Ultimately what it comes down to is this:
Suite configs have an option only_sanity_test_required/only_hwtest_sanity_required
that will run on any build that has passed at least the sanity HW test.
This is so that we can use builds that may have failed (this is the
"relaxed builds" feature).

The relaxed builds feature is known to be broken, which is why I
hadn't paid it much attention. But it turns out that if this suite option is
set, we switch to using the relaxed buildset (which conceptually should be
a superset of passed_builds). We were not adding Rubik builds into the
relaxed build set, so any suite with this option set was not seeing
Rubik boards (kevin-kernelnext and atlas-kernelnext).

BUG=b:214254790,b:227351798
TEST=will monitor in staging

Change-Id: I0c1e9e7c03a198f2ebf9c783623a8305165d4604
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/suite_scheduler/+/3561034
Commit-Queue: Jack Neus <jackneus@google.com>
Tested-by: Jack Neus <jackneus@google.com>
Auto-Submit: Jack Neus <jackneus@google.com>
Reviewed-by: George Engelbrecht <engeg@google.com>
Commit-Queue: George Engelbrecht <engeg@google.com>
diff --git a/build_lib.py b/build_lib.py
index bf172c8..7ae2169 100644
--- a/build_lib.py
+++ b/build_lib.py
@@ -304,7 +304,7 @@
       cros_board_list, all_branch_rubik_builds, rubik_build_targets=rubik_build_targets,
       use_rubik=True)
   relaxed_builds_dict = buildinfo_list_to_branch_build_dict(
-      cros_board_list, relaxed_builds + all_branch_builds,
+      cros_board_list, relaxed_builds + all_branch_builds + all_branch_rubik_builds,
       rubik_build_targets=rubik_build_targets)
 
   return dict(branch_builds_dict, **rubik_branch_builds_dict), relaxed_builds_dict