fix: Fix description of cps.streamingPull.parallelStreams (#396)

The current description is a duplicate of cps.streamingPull.flowControlBytes.

Looking at the code, the parallelStreams property corresponds to Subscriber.Builder.setParallelPullCount in the client library:

(https://cloud.google.com/java/docs/reference/google-cloud-pubsub/latest/com.google.cloud.pubsub.v1.Subscriber.Builder#com_google_cloud_pubsub_v1_Subscriber_Builder_setParallelPullCount_int_)

Author: VeronicaWasson

README.md

@@ -185,7 +185,7 @@ configurations:
 | cps.streamingPull.enabled              | Boolean                                                            | false                        | Whether to use streaming pull for the connector to connect to Pub/Sub. If provided, cps.maxBatchSize is ignored.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
 | cps.streamingPull.flowControlMessages  | Long                                                               | 1,000                        | The maximum number of outstanding messages per task when using streaming pull.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
 | cps.streamingPull.flowControlBytes     | Long                                                               | 100L * 1024 * 1024 (100 MiB) | The maximum number of outstanding message bytes per task when using streaming pull.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
-| cps.streamingPull.parallelStreams      | Integer                                                            | 1                            | The maximum number of outstanding message bytes per task when using streaming pull.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
+| cps.streamingPull.parallelStreams      | Integer                                                            | 1                            | The number of streams to pull messages from the subscription when using streaming pull.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
 | cps.streamingPull.maxAckExtensionMs    | Long                                                               | 0                            | The maximum number of milliseconds the subscribe deadline will be extended to in milliseconds when using streaming pull. A value of `0` implies the java-pubsub library default value.                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
 | cps.streamingPull.maxMsPerAckExtension | Long                                                               | 0                            | The maximum number of milliseconds to extend the subscribe deadline for at a time when using streaming pull. A value of `0` implies the java-pubsub library default value.                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |