Adding this in the hope it helps others trying to test Ola's script in AWS RDS.
I have created a 'DBA' database on a test RDS instance and installed the following parts of Ola Hallengren's maintenance scripts to this new DB.
I did test running the full maintenance script but you get the following errors, but the script still created the agents jobs I needed for integrity / index.
Msg 262, Level 14, State 1, Line 69
CREATE TABLE permission denied in database 'master'.
Msg 262, Level 14, State 18, Procedure CommandExecute, Line 1 [Batch Start Line 96]
CREATE PROCEDURE permission denied in database 'master'.
I still hit errors when running the update statistics job because it was attempting to update them against the rdsadmin database, commenting this database out in the agent job means my job now works.