Fix lineage in BQ plugins

Author: CuriousVini

src/main/java/co/cask/gcp/bigquery/BigQuerySink.java

@@ -121,8 +121,10 @@ public void prepareRun(BatchSinkContext context) throws Exception {
       BigQueryFileFormat.NEWLINE_DELIMITED_JSON,
       TextOutputFormat.class);
 
-    setOutputFormat(context);
+    // Both emitLineage and setOutputFormat internally try to create an external dataset if it does not already exists.
+    // We call emitLineage before since it creates the dataset with schema which .
     emitLineage(context, fields);
+    setOutputFormat(context);
   }
 
   @Override

src/main/java/co/cask/gcp/bigquery/BigQuerySource.java

@@ -112,8 +112,10 @@ public void prepareRun(BatchSourceContext context) throws Exception {
     job.setOutputKeyClass(LongWritable.class);
     job.setOutputKeyClass(Text.class);
 
-    setInputFormat(context);
+    // Both emitLineage and setOutputFormat internally try to create an external dataset if it does not already exists.
+    // We call emitLineage before since it creates the dataset with schema which .
     emitLineage(context);
+    setInputFormat(context);
   }
 
   @Override