Disable flaky test: PageLanguageDetectionConflict

This CL disables the test:
 - TranslateManagerBrowserTest.PageLanguageDetectionConflict

It was reported as flaky and appears to timeout the first time it is
run but succeed the second.

Bug: 1148703
Change-Id: I2e14df16d8b42fc6acab49212adf5020d426b54b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2538093
Commit-Queue: Trevor  Perrier <perrier@chromium.org>
Reviewed-by: Megan Jablonski <megjablon@chromium.org>
Reviewed-by: Scott Little <sclittle@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827393}

chrome/browser/translate/translate_manager_browsertest.cc

@@ -405,8 +405,9 @@ IN_PROC_BROWSER_TEST_F(TranslateManagerBrowserTest, PageLanguageDetection) {
 // Tests that the language detection / HTML attribute override works correctly.
 // For languages in the whitelist, the detected language should override the
 // HTML attribute. For all other languages, the HTML attribute should be used.
+// Flaky on all platforms. https://crbug.com/1148703
 IN_PROC_BROWSER_TEST_F(TranslateManagerBrowserTest,
-                       PageLanguageDetectionConflict) {
+                       DISABLED_PageLanguageDetectionConflict) {
   ChromeTranslateClient* chrome_translate_client = GetChromeTranslateClient();
 
   // The InProcessBrowserTest opens a new tab, let's wait for that first.