Small changes for okio consistency

wire-runtime/src/commonMain/kotlin/com/squareup/wire/MessageSink.kt

@@ -16,6 +16,7 @@
 package com.squareup.wire
 
 import kotlin.Throws
+import okio.Closeable
 import okio.IOException
 
 /**
@@ -39,8 +40,11 @@ import okio.IOException
  * You should ensure that such backpressure propagates to the originator of outbound messages.
  *
  * Instances of this interface are not safe for concurrent use.
+ *
+ * Closing a sink will terminate the stream and release its resources. If this has not been canceled
+ * this signals a normal completion of the stream.
  */
-expect interface MessageSink<in T : Any> {
+interface MessageSink<in T : Any> : Closeable {
   /**
    * Encode [message] to bytes and enqueue the bytes for delivery, waiting if necessary until the
    * delivery channel has capacity for the encoded message.
@@ -60,11 +64,4 @@ expect interface MessageSink<in T : Any> {
    */
   @Throws(IOException::class)
   fun cancel()
-
-  /**
-   * Terminate the stream and release its resources. If this has not been canceled this signals a
-   * normal completion of the stream.
-   */
-  @Throws(IOException::class)
-  fun close()
 }

wire-runtime/src/commonMain/kotlin/com/squareup/wire/MessageSource.kt

@@ -16,6 +16,7 @@
 package com.squareup.wire
 
 import kotlin.Throws
+import okio.Closeable
 import okio.IOException
 
 /**
@@ -35,7 +36,7 @@ import okio.IOException
  *
  * Instances of this interface are not safe for concurrent use.
  */
-expect interface MessageSource<out T : Any> {
+interface MessageSource<out T : Any> : Closeable {
   /**
    * Read the next length-prefixed message on the stream and return it. Returns null if there are
    * no further messages on this stream.
@@ -45,7 +46,4 @@ expect interface MessageSource<out T : Any> {
    */
   @Throws(IOException::class)
   fun read(): T?
-
-  @Throws(IOException::class)
-  fun close()
 }

wire-runtime/src/jvmMain/kotlin/com/squareup/wire/EnumAdapter.kt

@@ -16,8 +16,8 @@
 package com.squareup.wire
 
 import com.squareup.wire.internal.identityOrNull
-import java.io.IOException
 import kotlin.reflect.KClass
+import okio.IOException
 
 /**
  * An abstract [ProtoAdapter] that converts values of an enum to and from integers.

wire-runtime/src/jvmMain/kotlin/com/squareup/wire/ProtoAdapter.kt

@@ -18,13 +18,13 @@
 package com.squareup.wire
 
 import com.squareup.wire.internal.createRuntimeMessageAdapter
-import java.io.IOException
 import java.io.InputStream
 import java.io.OutputStream
 import kotlin.reflect.KClass
 import okio.BufferedSink
 import okio.BufferedSource
 import okio.ByteString
+import okio.IOException
 import okio.buffer
 import okio.sink
 import okio.source