Merge pull request #3576 from Unity-Technologies/develop-shortentrainerconfigs

[change] Reduce max_steps for PushBlock and Bouncer

config/sac_trainer_config.yaml

     summary_freq: 20000
 
 PushBlock:
-    max_steps: 1.5e7
+    max_steps: 2e6
     init_entcoef: 0.05
     hidden_units: 256
     summary_freq: 60000

config/trainer_config.yaml

 
 Bouncer:
     normalize: true
-    max_steps: 7.0e6
+    max_steps: 4.0e6
-    max_steps: 1.5e7
+    max_steps: 2.0e6
     batch_size: 128
     buffer_size: 2048
     beta: 1.0e-2