Rename rwTxn to readWriteTxn

Author: ShuranZhang

samples/snippets/src/main/java/com/example/spanner/ChangeStreamsTxnExclusionSample.java

@@ -38,12 +38,12 @@ static void setExcludeTxnFromChangeStreams() {
         SpannerOptions.newBuilder().setProjectId(projectId).build().getService()) {
       final DatabaseClient databaseClient =
           spanner.getDatabaseClient(DatabaseId.of(projectId, instanceId, databaseId));
-      rwTxnExcludedFromChangeStreams(databaseClient);
+      readWriteTxnExcludedFromChangeStreams(databaseClient);
     }
   }
 
   // [START spanner_set_exclude_txn_from_change_streams]
-  static void rwTxnExcludedFromChangeStreams(DatabaseClient client) {
+  static void readWriteTxnExcludedFromChangeStreams(DatabaseClient client) {
     // Exclude the transaction from allowed tracking change streams with alloww_txn_exclusion=true.
     // This exclusion will be applied to all the individual operations inside this transaction.
     client

samples/snippets/src/test/java/com/example/spanner/ChangeStreamsTxnExclusionSampleIT.java

@@ -90,7 +90,8 @@ public void removeTestData() {
   public void testSetExcludeTxnFromChangeStreamsSampleSample() throws Exception {
     final DatabaseClient client = spanner.getDatabaseClient(databaseId);
     String out =
-        runSample(() -> ChangeStreamsTxnExclusionSample.rwTxnExcludedFromChangeStreams(client));
+        runSample(
+            () -> ChangeStreamsTxnExclusionSample.readWriteTxnExcludedFromChangeStreams(client));
     assertThat(out).contains("New singer inserted.");
     assertThat(out).contains("Singer first name updated.");
   }