[BUG] Recurrent MADQN failing with shape errors on Pong environment

[AsadJeewa]

Describe the bug

Recurrent MADQN example is failing with shape errors on Pong environment

To Reproduce

Steps to reproduce the behavior:
1.python3 examples/tf/petting_zoo/atari/pong/recurrent/decentralised/run_madqn.py

Expected behavior

Nodes should run as normal and not be halted by ValueError: Dimensions must be equal, but are 19 and 32 for '{{node SelectV2}} = SelectV2[T=DT_FLOAT](Cast, strided_slice_5, SelectV2/e)' with input shapes: [19,32], [19,32,18], [].

Context (Environment)

• Mava latest on dev branch as of 23-02-2022
• Ubuntu 20.04 (not relevant)

Additional context

Possible Solution

Fix action masking for this environment