add shifted dot and reg dot nn file

Project/Assets/ML-Agents/Examples/Walker/TFModels/WalkerDynamicMovingTarget_25M_Cloud.nn.meta

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Project/Assets/ML-Agents/Examples/Walker/TFModels/WalkerDynamicMovingTarget_NEWDOT_25M_Cloud.nn.meta

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+    11400002: model data
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
+  script: {fileID: 11500000, guid: 19ed1486aa27d4903b34839f37b8f69f, type: 3}