Hide the isStreaming PipelineOption

This is automatically inferred when necessary in all existing runners.
Users should not need to set it unless they wish to force an alternative
execution environment in a runner that respects this flag while running
a Bounded Pipeline.

sdks/java/core/src/main/java/org/apache/beam/sdk/options/StreamingOptions.java

@@ -25,7 +25,9 @@ public interface StreamingOptions extends
   /**
    * Set to true if running a streaming pipeline.
    */
-  @Description("Set to true if running a streaming pipeline.")
+  @Description("Set to true if running a streaming pipeline. This will be automatically set to "
+      + "true if the pipeline contains an Unbounded PCollection.")
+  @Hidden
   boolean isStreaming();
   void setStreaming(boolean value);
 }