indexer-common: replace usage of in for undefined check

A property may be present in an object but have value undefined.
Therefore, x in obj is not the same as obj.x === undefined.

packages/indexer-common/src/indexer-management/types.ts

@@ -165,12 +165,14 @@ const Caip2ByChainId: { [key: number]: string } = {
 /// or chain ids (numbers).
 export function resolveChainId(key: number | string): string {
   if (typeof key === 'number') {
-    if (key in Caip2ByChainId) {
-      return Caip2ByChainId[key]
+    const chainId = Caip2ByChainId[key]
+    if (chainId !== undefined) {
+      return chainId
     }
   } else {
-    if (key in Caip2ByChainAlias) {
-      return Caip2ByChainAlias[key]
+    const chainId = Caip2ByChainAlias[key]
+    if (chainId !== undefined) {
+      return chainId
     }
   }
   throw new Error(`Failed to resolve CAIP2 ID from the provided network alias: ${key}`)