Move FIRST_BUFFER_SIZE to make checkstyle happy

Author: ejona86

core/src/main/java/io/grpc/internal/MessageFramer.java

@@ -391,6 +391,8 @@ public void write(byte[] b, int off, int len) {
    * {@link OutputStream}.
    */
   private final class BufferChainOutputStream extends OutputStream {
+    private static final int FIRST_BUFFER_SIZE = 4096;
+
     private final List<WritableBuffer> bufferList = new ArrayList<>();
     private WritableBuffer current;
 
@@ -409,8 +411,6 @@ public void write(int b) {
       write(singleByte, 0, 1);
     }
 
-    private static final int FIRST_BUFFER_SIZE = 4096;
-
     @Override
     public void write(byte[] b, int off, int len) {
       if (current == null) {