Regarding model.execute issue in CameraScreen.

[KP1104]

The shape of dict['input'] provided in model.execute(dict) must be [1,256,256,3], but was [1,256,256,4]
at http://192.168.2.105:19000/node_modules/expo/AppEntry.bundle?platform=android&dev=true&hot=false&strict=false&minify=false:182291:21 in assert
at node_modules/@tensorflow/tfjs-converter/dist/executor/graph_executor.js:454:32 in Object.keys.forEach$argument_0
at node_modules/@tensorflow/tfjs-converter/dist/executor/graph_executor.js:443:4 in
at node_modules/@tensorflow/tfjs-converter/dist/executor/graph_executor.js:177:8 in GraphExecutor.prototype.execute
at node_modules/@tensorflow/tfjs-converter/dist/executor/graph_model.js:311:4 in
at node_modules/@tensorflow-models/handpose/dist/hand.js:35:40 in tf.tidy$argument_0
at http://192.168.2.105:19000/node_modules/expo/AppEntry.bundle?platform=android&dev=true&hot=false&strict=false&minify=false:287520:70 in estimateHandBounds$
at http://192.168.2.105:19000/node_modules/expo/AppEntry.bundle?platform=android&dev=true&hot=false&strict=false&minify=false:287784:92 in estimateHand$
at node_modules/@tensorflow-models/handpose/dist/index.js:62:13 in tf.tidy$argument_0