android: disable flaky tests in chrome_public_test_apk on emulator

Bug: 1046059
Change-Id: I5a29498d1d915560fa4d108f8666dd3da8032f1e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2109145Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Haiyang Pan <hypan@google.com>
Cr-Commit-Position: refs/heads/master@{#751551}

testing/buildbot/filters/android.emulator.chrome_public_test_apk.filter

@@ -97,3 +97,10 @@
 
 # crbug.com/1062058
 -org.chromium.chrome.browser.customtabs.DetachedResourceRequestTest.testSafeBrowsingMainResourceWithSplitCache
+
+# crbug.com/1062838
+-org.chromium.chrome.browser.offlinepages.prefetch.PrefetchFeedFlowTest.testPrefetchForbiddenByServer_FullBrowser
+
+# crbug.com/1062843
+-org.chromium.chrome.browser.banners.AppBannerManagerTest.testAppInstalledModalNativeAppBannerCustomTab
+-org.chromium.chrome.browser.banners.AppBannerManagerTest.testModalNativeAppBannerCanBeTriggeredMultipleTimesCustomTab