Revert "Disable RunAppAsync and RunAppAsyncRedirectStderrToStdout"

This reverts commit f4f866ce28.

Reason for revert: These tests should not be disabled. The culprit is
fixed per crbug.com/1233361

Original change's description:
> Disable RunAppAsync and RunAppAsyncRedirectStderrToStdout
>
> The tests are blocking the CQ due to flakiness.
>
> Bug: chromium:1233361
> Change-Id: Ib0283e201c271379364a177bea130d63322eee53
> Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3058233
> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

Bug: chromium:1233361
Change-Id: I24682f74d790d40f58a9526aaaaa842c3df23ec0
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3058502
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

src/tests/test_utils/runner/TestSuite_unittest.cpp

@@ -89,8 +89,7 @@ class TestSuiteTest : public testing::Test
 
         if (validateStderr)
         {
-            // TODO: Uncomment when crbug.com/1233361 is resolved.
-            // EXPECT_EQ(process->getStderr(), "");
+            EXPECT_EQ(process->getStderr(), "");
         }
 
         if (gVerbose)

util/test_utils_unittest.cpp

@@ -139,11 +139,10 @@ TEST(TestUtils, MAYBE_CreateAndDeleteFileInTempDir)
 #    define MAYBE_RunApp DISABLED_RunApp
 #    define MAYBE_RunAppAsync DISABLED_RunAppAsync
 #    define MAYBE_RunAppAsyncRedirectStderrToStdout DISABLED_RunAppAsyncRedirectStderrToStdout
-// TODO: flaky failures. http://crbug.com/1233361
 #else
-#    define MAYBE_RunApp DISABLED_RunApp
-#    define MAYBE_RunAppAsync DISABLED_RunAppAsync
-#    define MAYBE_RunAppAsyncRedirectStderrToStdout DISABLED_RunAppAsyncRedirectStderrToStdout
+#    define MAYBE_RunApp RunApp
+#    define MAYBE_RunAppAsync RunAppAsync
+#    define MAYBE_RunAppAsyncRedirectStderrToStdout RunAppAsyncRedirectStderrToStdout
 #endif  // defined(ANGLE_PLATFORM_ANDROID)
 
 // Test running an external application and receiving its output