Remove the tests filtered for being flaky on android.

I ran the listed tests with --repeat 100. Some of them are slow and
didn't complete 100 with the 1200s swarming timeout.

Tests that passed 100 times

NavigationControllerBrowserTest.ReplacedNavigationEntryData_Back
NavigationControllerBrowserTest.BackOnBrowserInitiatedErrorPageNavigation
NavigationControllerBrowserTest.BrowserInitiatedLoadPostCommitErrorPageForSubframe
NavigationControllerBrowserTest.PageStateAfterForwardInCompetingFrames
TouchpadPinchBrowserTest.*
RenderViewHostTest.IsFocusedElementEditable
NavigationControllerBrowserTest.BackSameDocumentAfterBlockedSubframe
TouchInputBrowserTest.*

Their logs
https://chromium-swarm.appspot.com/task?id=480f3577f603df10
https://chromium-swarm.appspot.com/task?id=480f35af96d38810
https://chromium-swarm.appspot.com/task?id=480f3529b3cb5b10
https://chromium-swarm.appspot.com/task?id=480f3560f9248710
https://chromium-swarm.appspot.com/task?id=480f3620d07eea10
https://chromium-swarm.appspot.com/task?id=480f35a40c170a10
https://chromium-swarm.appspot.com/task?id=480f35c19a626c10
https://chromium-swarm.appspot.com/task?id=480f35df2a874410

Tests that passed 100% but only ran ~30 times

MSE_ExternalClearKey/EncryptedMediaTest.*
IndexedDBBrowserTest*
MSE_ClearKey/EncryptedMediaTest.*
MHTMLGenerationTest/MHTMLGenerationTest.*

Their logs

Task: https://chromium-swarm.appspot.com/task?id=480f58227f406610
Task: https://chromium-swarm.appspot.com/task?id=480f351ac8bdb010
Task: https://chromium-swarm.appspot.com/task?id=480f580b0085c010
Task: https://chromium-swarm.appspot.com/task?id=480f5ec378dd1210

Bug: 1016230
Change-Id: Iad60171b7f8f3a54af4f76e4755e6568ac73514c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1874070
Commit-Queue: Fergal Daly <fergal@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Fergal Daly <fergal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708887}

testing/buildbot/filters/bfcache.content_browsertests.filter

@@ -50,17 +50,3 @@
 # histogram is not recorded before the end of the test.
 -SignedExchangeRequestHandlerBrowserTest.Simple/3
 -SignedExchangeRequestHandlerBrowserTest.VariantMatch/3
-
-# Flaky on android only, need to be triaged, see https://crbug.com/1006267.
--IndexedDBBrowserTest*
--MHTMLGenerationTest/MHTMLGenerationTest.*
--MSE_ClearKey/EncryptedMediaTest.*
--MSE_ExternalClearKey/EncryptedMediaTest.*
--NavigationControllerBrowserTest.BackOnBrowserInitiatedErrorPageNavigation
--NavigationControllerBrowserTest.BackSameDocumentAfterBlockedSubframe
--NavigationControllerBrowserTest.BrowserInitiatedLoadPostCommitErrorPageForSubframe
--NavigationControllerBrowserTest.PageStateAfterForwardInCompetingFrames
--NavigationControllerBrowserTest.ReplacedNavigationEntryData_Back
--RenderViewHostTest.IsFocusedElementEditable
--TouchInputBrowserTest.*
--TouchpadPinchBrowserTest.*