fix(ctb): bug in L2 genesis script (#3068)

Fixes a bug in the Bedrock L2 genesis script where storage slots were
being set in the implementation rather than the proxy, which (obviously)
broke various things that the SDK relies on.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

.changeset/clever-news-smile.md

+---
+'@eth-optimism/contracts-bedrock': patch
+---
+
+Fixes a bug in the L2 Bedrock genesis script

packages/contracts-bedrock/tasks/genesis-l2.ts

@@ -170,6 +170,28 @@ task('genesis-l2', 'create a genesis config')
       }
 
       if (predeployAddrs.has(ethers.utils.getAddress(addr))) {
+        const predeploy = Object.entries(predeploys).find(([, address]) => {
+          return ethers.utils.getAddress(address) === addr
+        })
+
+        // Really shouldn't happen, since predeployAddrs is a set generated from predeploys.
+        if (predeploy === undefined) {
+          throw new Error('could not find address')
+        }
+
+        const name = predeploy[0]
+        if (variables[name]) {
+          const storageLayout = await getStorageLayout(hre, name)
+          if (storageLayout === undefined) {
+            throw new Error(`cannot find storage layout for ${name}`)
+          }
+          const slots = computeStorageSlots(storageLayout, variables[name])
+
+          for (const slot of slots) {
+            alloc[addr].storage[slot.key] = slot.val
+          }
+        }
+
         alloc[addr].storage[implementationSlot] = toCodeAddr(addr)
       }
     }
@@ -247,16 +269,6 @@ task('genesis-l2', 'create a genesis config')
         code: artifact.deployedBytecode,
         storage: {},
       }
-
-      const storageLayout = await getStorageLayout(hre, name)
-      if (storageLayout === undefined) {
-        throw new Error(`cannot find storage layout for ${name}`)
-      }
-      const slots = computeStorageSlots(storageLayout, variables[name])
-
-      for (const slot of slots) {
-        alloc[allocAddr].storage[slot.key] = slot.val
-      }
     }
 
     const portal = await hre.deployments.get('OptimismPortalProxy')