[iOS][MF] Reenable failing tests

Some modifications has been made to make all the manual fallback
tests more robust. As it can be seen in the bots of the CQ
these test are not failing anymore.

Bug: 1007421, 1007455
Change-Id: I30b2c454a42925dc64a6226788a26db3f760ef5d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1859967
Auto-Submit: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706040}

ios/chrome/browser/ui/autofill/manual_fill/fallback_coordinator_egtest.mm

@@ -446,11 +446,6 @@ void DockKeyboard() {
 // Tests that the manual fallback view concedes preference to the system picker
 // for selection elements.
 - (void)testPickerDismissesManualFallback {
-  if (@available(iOS 13, *)) {
-    // TODO(crbug.com/1007455): Enable this test.
-    EARL_GREY_TEST_DISABLED(@"The test is flaky on iOS 13");
-  }
-
   // Add the profile to be used.
   AddAutofillProfile(_personalDataManager);
 
@@ -703,8 +698,7 @@ void DockKeyboard() {
 // Tests the mediator stops observing objects when the incognito BVC is
 // destroyed. Waiting for dealloc was causing a race condition with the
 // autorelease pool, and some times a DCHECK will be hit.
-// TODO(crbug.com/1007421): This test is flaky on all configurations.
-- (void)FLAKY_testOpeningIncognitoTabsDoNotLeak {
+- (void)testOpeningIncognitoTabsDoNotLeak {
   const GURL URL = self.testServer->GetURL(kFormHTMLFile);
   std::string webViewText("Profile form");
   AddAutofillProfile(_personalDataManager);