Re-enable some tests for flatten.

Author: shunping

runners/prism/java/build.gradle

@@ -111,10 +111,10 @@ def sickbayTests = [
 
     // Java side dying during execution.
     // https://github.com/apache/beam/issues/32930
-    'org.apache.beam.sdk.transforms.FlattenTest.testFlattenMultipleCoders',
+    // 'org.apache.beam.sdk.transforms.FlattenTest.testFlattenMultipleCoders',
     // Stream corruption error java side: failed:java.io.StreamCorruptedException: invalid stream header: 206E6F74
     // Likely due to prism't coder changes.
-    'org.apache.beam.sdk.transforms.FlattenTest.testFlattenWithDifferentInputAndOutputCoders2',
+    // 'org.apache.beam.sdk.transforms.FlattenTest.testFlattenWithDifferentInputAndOutputCoders2',
 
     // java.lang.IllegalStateException: Output with tag Tag<output> must have a schema in order to call getRowReceiver
     // Ultimately because getRoeReceiver code path SDK side isn't friendly to LengthPrefix wrapping of row coders.