Add gmock matcher support for comparing flatbuffers

This makes it easier to compare flatbuffers in tests.

Change-Id: Iabd1038f7ce9dfc3edf1162f2d7b0485cdda3b90
diff --git a/aos/BUILD b/aos/BUILD
index 86aa433..790f845 100644
--- a/aos/BUILD
+++ b/aos/BUILD
@@ -463,6 +463,7 @@
     target_compatible_with = ["@platforms//os:linux"],
     deps = [
         ":configuration",
+        "//aos/testing:flatbuffer_eq",
         "//aos/testing:googletest",
         "//aos/testing:test_logging",
     ],