Switch gtest_main over to using gflags

This lets us use gflags in our tests in other places

Change-Id: I70976a5165217549f1bc2b7bee64316a646756b3
diff --git a/aos/testing/BUILD b/aos/testing/BUILD
index 33794a5..ed410b1 100644
--- a/aos/testing/BUILD
+++ b/aos/testing/BUILD
@@ -7,6 +7,7 @@
     visibility = ["//visibility:public"],
     deps = [
         "//third_party/googletest:gtest",
+        "@com_github_gflags_gflags//:gflags",
     ],
 )
 
@@ -23,8 +24,8 @@
     deps = [
         ":googletest",
         "//aos:once",
-        "//aos/mutex:mutex",
         "//aos/logging:implementations",
+        "//aos/mutex",
     ],
 )
 
@@ -68,8 +69,8 @@
     deps = [
         ":test_logging",
         "//aos:queues",
-        "//aos/logging",
         "//aos/ipc_lib:shared_mem",
+        "//aos/logging",
     ],
 )