Suppress nullability warnings.

Original Pull Request: #5067

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/ReactiveMongoDatabaseUtils.java

@@ -156,6 +156,7 @@ private static Mono<MongoDatabase> getMongoDatabaseOrDefault(@Nullable String db
 		return StringUtils.hasText(dbName) ? factory.getMongoDatabase(dbName) : factory.getMongoDatabase();
 	}
 
+	@SuppressWarnings("NullAway")
 	private static Mono<ClientSession> doGetSession(TransactionSynchronizationManager synchronizationManager,
 			ReactiveMongoDatabaseFactory dbFactory, SessionSynchronization sessionSynchronization) {
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/IndexOperationsAdapter.java

@@ -34,6 +34,7 @@ public interface IndexOperationsAdapter extends IndexOperations {
 	 * @param reactiveIndexOperations must not be {@literal null}.
 	 * @return never {@literal null}
 	 */
+	@SuppressWarnings("NullAway")
 	static IndexOperationsAdapter blocking(ReactiveIndexOperations reactiveIndexOperations) {
 
 		Assert.notNull(reactiveIndexOperations, "ReactiveIndexOperations must not be null");