[Sheriff] Disable flaky test DeclarativeApiTest.PersistRules on Linux

It is flaky as part of network_service_browser_tests on
Linux Tests (dbg)(1).

TBR=dvadym

Bug: 347159
Change-Id: I72e204f87334d94723c26b998d4b649e187c78f0
Reviewed-on: https://chromium-review.googlesource.com/1148774Reviewed-by: Derek Cheng <imcheng@chromium.org>
Commit-Queue: Derek Cheng <imcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577639}

chrome/browser/extensions/api/declarative/declarative_apitest.cc

@@ -150,7 +150,13 @@ IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, PRE_PersistRules) {
   ASSERT_TRUE(RunExtensionTest("declarative/redirect_to_data")) << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, PersistRules) {
+// Disabled on Linux for flakiness: https://crbug.com/347159
+#if defined(OS_LINUX)
+#define MAYBE_PersistRules DISABLED_PersistRules
+#else
+#define MAYBE_PersistRules PersistRules
+#endif
+IN_PROC_BROWSER_TEST_F(DeclarativeApiTest, MAYBE_PersistRules) {
   ui_test_utils::NavigateToURL(browser(), GURL(kArbitraryUrl));
   EXPECT_EQ(kTestTitle, GetTitle());
 }