Fix local flaky test attempts reusing the same TEST_TMPDIR.

When a test is run with --test_strategy=local (or equivalent Google-specific
strategies), flaky retry attempts were reusing the same TestRunnerSpawn
instance. This caused the subsequent attempts to use the same TEST_TMPDIR
without it being properly cleared, potentially leading to interference between
test runs.

RELNOTES: None.
PiperOrigin-RevId: 885161547
Change-Id: Ia997c41039f02874f6f0d8fb74132cbe90d3a544

src/main/java/com/google/devtools/build/lib/exec/StandaloneTestStrategy.java

diff --git a/src/main/java/com/google/devtools/build/lib/exec/StandaloneTestStrategy.java b/src/main/java/com/google/devtools/build/lib/exec/StandaloneTestStrategy.java
index 439057b..6dcf1fb 100644
--- a/src/main/java/com/google/devtools/build/lib/exec/StandaloneTestStrategy.java
+++ b/src/main/java/com/google/devtools/build/lib/exec/StandaloneTestStrategy.java
@@ -615,6 +615,12 @@
               .build();
       finalizeTest(standaloneTestResult, failedAttempts);
     }
+
+    @Override
+    public TestRunnerSpawn getFlakyRetryRunner(List<SpawnResult> previousAttemptResults)
+        throws ExecException, InterruptedException {
+      return createTestRunnerSpawn(testAction, actionExecutionContext);
+    }
   }
 
   private static TestExecException createTestExecException(