Simplify some compareTo operations

I believe they have intrinsics even for the long-form Integer.compareTo(Integer.valueOf(a), Integer.valueOf(b)) format which avoids the intermediate allocation.

So this probably won't make things faster, just makes the code a little cleaner.

Integer.compare was added in Java 1.7 which seems safe. Added to Android in SDK 19, which is less than the 21 minSDK supported by protobuf: 303239d74d

PiperOrigin-RevId: 653438420

java/core/src/main/java/com/google/protobuf/ByteString.java

@@ -287,13 +287,12 @@ public abstract class ByteString implements Iterable<Byte>, Serializable {
 
           while (formerBytes.hasNext() && latterBytes.hasNext()) {
             int result =
-                Integer.valueOf(toInt(formerBytes.nextByte()))
-                    .compareTo(toInt(latterBytes.nextByte()));
+                Integer.compare(toInt(formerBytes.nextByte()), toInt(latterBytes.nextByte()));
             if (result != 0) {
               return result;
             }
           }
-          return Integer.valueOf(former.size()).compareTo(Integer.valueOf(latter.size()));
+          return Integer.compare(former.size(), latter.size());
         }
       };
 

java/core/src/main/java/com/google/protobuf/Descriptors.java

@@ -2343,7 +2343,7 @@ public final class Descriptors {
         new Comparator<EnumValueDescriptor>() {
           @Override
           public int compare(EnumValueDescriptor o1, EnumValueDescriptor o2) {
-            return Integer.valueOf(o1.getNumber()).compareTo(o2.getNumber());
+            return Integer.compare(o1.getNumber(), o2.getNumber());
           }
         };