Fix assorted ErrorProne warnings.

RELNOTES: None.
PiperOrigin-RevId: 167574104
diff --git a/src/main/java/com/google/devtools/build/lib/packages/Package.java b/src/main/java/com/google/devtools/build/lib/packages/Package.java
index 9e4ab19..8a17fbd 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Package.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Package.java
@@ -47,6 +47,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import javax.annotation.Nullable;
 
@@ -1167,7 +1168,7 @@
       }
       if (!((InputFile) cacheInstance).isVisibilitySpecified()
           || cacheInstance.getVisibility() != visibility
-          || cacheInstance.getLicense() != license) {
+          || !Objects.equals(cacheInstance.getLicense(), license)) {
         targets.put(filename, new InputFile(
             pkg, cacheInstance.getLabel(), cacheInstance.getLocation(), visibility, license));
       }