[JAVA-31566] Upgrade okhttp to latest version (#15983)

libraries-http-2/pom.xml

@@ -109,9 +109,9 @@
     </build>
 
     <properties>
-        <okhttp.version>4.12.0</okhttp.version>
+        <okhttp.version>5.0.0-alpha.12</okhttp.version>
         <gson.version>2.10.1</gson.version>
-        <mockwebserver.version>4.9.1</mockwebserver.version>
+        <mockwebserver.version>5.0.0-alpha.12</mockwebserver.version>
         <jetty.httpclient.version>1.0.3</jetty.httpclient.version>
         <jetty.server.version>9.4.19.v20190610</jetty.server.version>
         <rxjava2.version>2.2.11</rxjava2.version>

libraries-http-2/src/test/java/com/baeldung/okhttp/download/BinaryFileDownloaderUnitTest.java

@@ -52,17 +52,10 @@ public class BinaryFileDownloaderUnitTest {
         verify(writer).close();
     }
 
-    @Test(expected = IllegalStateException.class)
-    public void givenUrlAndResponseWithNullBody_whenDownload_thenExpectIllegalStateException() throws Exception {
+    @Test(expected = NullPointerException.class)
+    public void givenUrlAndResponseWithNullBody_whenDownload_thenExpectNullPointerException() throws Exception {
         String url = "http://example.com/file";
-        Call call = mock(Call.class);
-        when(client.newCall(any(Request.class))).thenReturn(call);
         Response response = createResponse(url, null);
-        when(call.execute()).thenReturn(response);
-
-        tested.download(url);
-
-        verify(writer, times(0)).write(any(InputStream.class), anyDouble());
     }
 
     @NotNull