update config to 3.5M steps

config/trainer_config.yaml

     time_horizon: 1000
     batch_size: 2024
     buffer_size: 20240
-    max_steps: 3e6
+    max_steps: 3.5e6
     summary_freq: 30000
     num_layers: 3
     hidden_units: 512
     time_horizon: 1000
     batch_size: 2024
     buffer_size: 20240
-    max_steps: 3e6
+    max_steps: 3.5e6
     summary_freq: 30000
     num_layers: 3
     hidden_units: 512