Continue making AspectTest.topLevelConflictDetected not flaky

A previous change recently make the preceding exception message check
insensitive to aspect analysis order. This one should be too.

RELNOTES: None.
PiperOrigin-RevId: 360913720
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/AspectTest.java b/src/test/java/com/google/devtools/build/lib/analysis/AspectTest.java
index a893ded..deaf363 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/AspectTest.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/AspectTest.java
@@ -989,8 +989,8 @@
                     "//foo:foo"));
     assertThat(exception)
         .hasMessageThat()
-        .contains(
-            "ConflictException: for foo/aspect.out, previous action: action 'Action for aspect 1',"
-                + " attempted action: action 'Action for aspect 2'");
+        .containsMatch(
+            "ConflictException: for foo/aspect.out, previous action: action 'Action for aspect .',"
+                + " attempted action: action 'Action for aspect .'");
   }
 }