scilla_call precompile errors with Built-in failed

[DrZoltanFazekas]

Here's an example of a transaction that involves an ERC20 -> ZRC2 interop call. The transaction succeeded but the ZRC2 transfer did not happen: https://explorer.zq2-protomainnet.zilliqa.com/tx/0xa86cfe1c38d6744eda04a62eac3119b54f562c575f7f1feac395a69e57da927e

The involved ZUSDT (ERC20) contract imported from ZQ1 calls the precompile with 21000 gas: https://github.com/Plunderswap/zrc2proxy/blob/3cefaae8c4e4c47647263a959cebd29183a8f336/contracts/EIP20ZRC2Proxy.sol

We've implemented a workaround to revert transactions in case the precompile is called with 21000 gas but the caller (ERC20) contract was not whitelisted. In the above case, however, ZUSDT was whitelisted in the proto-mainnet config file, so the interop call should have worked with 21000 gas: 0x2274005778063684fbB1BfA96a2b725dC37D75f9

The precompile failed, the relevant section of the trace says:

            {
                "type": "call",
                "action": {
                    "from": "0x2274005778063684fbb1bfa96a2b725dc37d75f9",
                    "callType": "call",
                    "gas": "0x5208",
                    "input": "0x000000000000000000000000818ca2e217e060ad17b7bd0124a483a1f66930a900000000000000000000000000000000000000000000000000000000000000a0000000000000000000000000000000000000000000000000000000000000000100000000000000000000000001a1005d41b9b27187ed6faadc05084e5ad6d59800000000000000000000000000000000000000000000000000000000000502a800000000000000000000000000000000000000000000000000000000000000085472616e73666572000000000000000000000000000000000000000000000000",
                    "to": "0x000000000000000000000000000000005a494c53",
                    "value": "0x0"
                },
                "error": "Built-in failed",
                "result": null,
                "subtraces": 0,
                "traceAddress": [
                    0,
                    1,
                    0,
                    0
                ]
            },