Use Bazel Preconditions variant which avoids varargs array creation

Reduces garbage.

--
MOS_MIGRATED_REVID=109914243
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java
index 302bb2b..174709b 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java
@@ -20,7 +20,6 @@
 import static com.google.devtools.build.lib.actions.FilesetTraversalParams.PackageBoundaryMode.REPORT_ERROR;
 
 import com.google.common.base.Function;
-import com.google.common.base.Preconditions;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -39,6 +38,7 @@
 import com.google.devtools.build.lib.testutil.FoundationTestCase;
 import com.google.devtools.build.lib.util.BlazeClock;
 import com.google.devtools.build.lib.util.Fingerprint;
+import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;