Remove some uses of MD5.

RELNOTES: None.
PiperOrigin-RevId: 275068452
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java
index 9d7811d..7effb91 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java
@@ -56,8 +56,6 @@
 import com.google.devtools.build.skyframe.SkyKey;
 import com.google.devtools.build.skyframe.SkyValue;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.security.MessageDigest;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -106,8 +104,7 @@
 
   @Test
   public void testUnreadableInputWithFsWithAvailableDigest() throws Throwable {
-    final byte[] expectedDigest = MessageDigest.getInstance("md5").digest(
-        "someunreadablecontent".getBytes(StandardCharsets.UTF_8));
+    final byte[] expectedDigest = {1, 2, 3, 4};
     setupRoot(
         new CustomInMemoryFs() {
           @Override