Add Rollback template to setup templates

setup-templates/template-incident/script/RollbackPause.s.sol

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.15;
+
+import "@base-contracts/script/universal/MultisigBuilder.sol";
+import "@eth-optimism-bedrock/contracts/L1/OptimismPortal.sol";
+
+contract RollbackUnpausePortal is MultisigBuilder {
+    address constant internal OPTIMISM_PORTAL_PROXY = vm.envAddress("OPTIMISM_PORTAL_PROXY"); // TODO: define OPTIMISM_PORTAL_PROXY=xxx in the .env file
+    address constant internal GUARDIAN = vm.envAddress("GUARDIAN"); // TODO: define GUARDIAN=xxx in the .env file
+
+    function _postCheck() internal override view {
+        OptimismPortal optimismPortal = OptimismPortal(payable(OPTIMISM_PORTAL_PROXY));
+        require(optimismPortal.paused() == false, "UnpausePortal: Portal did not get unpaused");
+    }
+
+    function _buildCalls() internal override view returns (IMulticall3.Call3[] memory) {
+        IMulticall3.Call3[] memory calls = new IMulticall3.Call3[](1);
+
+        calls[0] = IMulticall3.Call3({
+            target: OPTIMISM_PORTAL_PROXY,
+            allowFailure: false,
+            callData: abi.encodeCall(
+                OptimismPortal.unpause, ()
+            )
+        });
+
+        return calls;
+    }
+
+    function _ownerSafe() internal override view returns (address) {
+        return GUARDIAN;
+    }
+
+    function _addOverrides(address _safe) internal override view returns (SimulationStateOverride memory) {
+        IGnosisSafe safe = IGnosisSafe(payable(_safe));
+        uint256 _nonce = _getNonce(safe);
+        return overrideSafeThresholdOwnerAndNonce(_safe, DEFAULT_SENDER, _nonce);
+    }
+
+    // This transaction expects that there will be a `Pause` transaction before this one
+    // but both txs will be signed ahead of time. Need to explicitly override the nonce to 
+    // ensure that the correct nonce is used in the sign, simulate and execution steps. 
+    function _getNonce(IGnosisSafe) internal override view returns (uint256 nonce) {
+        nonce = vm.envUint("ROLLBACK_NONCE");
+    }
+}