[Infra] Stop including AdMob in zip builds (#15024)

Author: ncooke3

FirebaseCore/CHANGELOG.md

@@ -7,6 +7,13 @@
 - [removed] **Breaking change**: Removed the following unused API.
   - `Options.androidClientID`
   - `Options.trackingID`
+- [removed] **Breaking change**: Firebase's zip and Carthage distributions of
+  the Google Mobile Ads SDK has been removed. Instead, the Google
+  Mobile Ads SDK binary distribution should be accessed from
+  https://developers.google.com/admob/ios/download. Note that _any existing
+  versions of the Firebase zip or Carthage distributions will
+  continue to be available and functional_. Learn more about this change
+  in our FAQ: https://firebase.google.com/support/faq/#admob-which-sdk. (#14408)
 - [removed] The deprecated Vertex AI in Firebase SDK (`FirebaseVertexAI`) has
   been removed. It has been replaced by the Firebase AI Logic
   SDK (`FirebaseAI`) to

ReleaseTooling/Sources/ZipBuilder/CarthageUtils.swift

@@ -319,8 +319,6 @@ extension CarthageUtils {
     var jsonFileName: String
     if product == "GoogleSignIn" {
       jsonFileName = "FirebaseGoogleSignIn"
-    } else if product == "Google-Mobile-Ads-SDK" {
-      jsonFileName = "FirebaseAdMob"
     } else {
       jsonFileName = product
     }

ReleaseTooling/Sources/ZipBuilder/ZipBuilder.swift

@@ -369,11 +369,8 @@ struct ZipBuilder {
     guard !podsToInstall.isEmpty else {
       fatalError("Failed to find versions for Firebase release")
     }
-    // We don't release Google-Mobile-Ads-SDK and GoogleSignIn, but we include their latest
+    // We don't release GoogleSignIn, but we include its latest
     // version for convenience in the Zip and Carthage builds.
-    podsToInstall.append(CocoaPodUtils.VersionedPod(name: "Google-Mobile-Ads-SDK",
-                                                    version: nil,
-                                                    platforms: ["ios"]))
     podsToInstall.append(CocoaPodUtils.VersionedPod(name: "GoogleSignIn",
                                                     version: nil,
                                                     platforms: ["ios"]))
@@ -486,8 +483,7 @@ struct ZipBuilder {
 
     // Skip Analytics and the pods bundled with it.
     let remainingPods = installedPods.filter {
-      $0.key == "Google-Mobile-Ads-SDK" ||
-        $0.key == "GoogleSignIn" ||
+      $0.key == "GoogleSignIn" ||
         (firebaseZipPods.contains($0.key) &&
           $0.key != "FirebaseAnalytics" &&
           $0.key != "Firebase" &&