Deflaked: Guarddog_impl_test (#14475)

Deflaked guarddog_impl_test; on overloaded machines it would sometimes flake under the real time system with both threads to included in the miss / megamiss events when only one should be.

Tested via 2000 runs, of which it all passed. Prior it would flake a few (~1-5)/1000 on slower / overloaded machines.

Commit Message: Deflaked guarddog_impl_test under real time system.
Additional Description:
Risk Level: low
Testing: test change.
Docs Changes: N/A
Release Notes: N/A
Platform Specific Features: N/A

Signed-off-by: Kevin Baichoo <kbaichoo@google.com>

test/server/guarddog_impl_test.cc

@@ -625,7 +625,19 @@ TEST_P(GuardDogActionsTest, MissShouldOnlyReportRelevantThreads) {
   // synchronize with the guard dog.
   guard_dog_->forceCheckForTest();
 
+  if (GetParam() == TimeSystemType::Real) {
+    // Touch the second_dog in case we overslept in the real time system
+    // and the guard dog timer goes off.
+    second_dog_->touch();
+  }
+
   time_system_->advanceTimeWait(std::chrono::milliseconds(51));
+
+  if (GetParam() == TimeSystemType::Real) {
+    // Touch the second_dog in case we overslept in the real time system
+    // and the prior "touch" was consumed.
+    second_dog_->touch();
+  }
   guard_dog_->forceCheckForTest();
 
   EXPECT_THAT(events_, ElementsAre("MISS : 10"));
@@ -687,7 +699,19 @@ TEST_P(GuardDogActionsTest, MegaMissShouldOnlyReportRelevantThreads) {
   // synchronize with the guard dog.
   guard_dog_->forceCheckForTest();
 
+  if (GetParam() == TimeSystemType::Real) {
+    // Touch the second_dog in case we overslept in the real time system
+    // and the guard dog timer goes off.
+    second_dog_->touch();
+  }
+
   time_system_->advanceTimeWait(std::chrono::milliseconds(51));
+
+  if (GetParam() == TimeSystemType::Real) {
+    // Touch the second_dog in case we overslept in the real time system
+    // and the prior "touch" was consumed.
+    second_dog_->touch();
+  }
   guard_dog_->forceCheckForTest();
 
   EXPECT_THAT(events_, ElementsAre("MEGAMISS : 10"));