Fix iOSResolver Xcode Project integration to not include unnecessary source files in Pods.

In Xcode Project integration mode, iOSResolver add all source code files in the Pods folder to the Unity iOS Xcode project, which could include unnecessary example source code in some Pods(e.g. ARCore iOS Pod).
This change adds additional check to only add source code file to the Unity iOS Xcode project if the source code file is included in the Pods Xcode project generated by cocoaPod.

Bug: 113513472

Change-Id: I494abd1bd6c694597ca24965068cee510f45aba8

Author: bopangzz

source/IOSResolver/src/IOSResolver.cs

@@ -2188,19 +2188,43 @@ public static void UpdateProjectDeps(
             podPathToProjectPaths[filename.Substring(podsDir.Length + 1)] =
                 filename.Substring(pathToBuiltProject.Length + 1);
         }
+
+        var podsProjectPath = GetProjectPath(podsDir, PODS_PROJECT_NAME);
+        UnityEditor.iOS.Xcode.PBXProject podsProject = null;
+
+        if (File.Exists(podsProjectPath)) {
+            podsProject = new UnityEditor.iOS.Xcode.PBXProject();
+            podsProject.ReadFromString(File.ReadAllText(podsProjectPath));
+        }
+
         // Add a reference to each source file in the target project.
         foreach (var podPathProjectPath in podPathToProjectPaths) {
-            project.AddFileToBuild(
-                target,
-                project.AddFile(podPathProjectPath.Value,
-                                podPathProjectPath.Value,
-                                UnityEditor.iOS.Xcode.PBXSourceTree.Source));
-            // Some source pods (e.g Protobuf) can include files relative to the Pod root,
-            // add include paths relative to the Pod's source files for this use case.
-            project.UpdateBuildProperty(
-                    new [] { target }, "USER_HEADER_SEARCH_PATHS",
-                    new [] { "$(SRCROOT)/" + Path.GetDirectoryName(podPathProjectPath.Value) },
-                    new string[] {});
+            // Get the relative path inside 'Pods/'.
+            var sourceFilePathInPod = podPathProjectPath.Value.Substring(PODS_DIR.Length + 1);
+
+            // Only add source files that are included in the Pod project, this way we
+            // can avoid adding source files that are not part of the Pod dependencies.
+            if(podsProject != null && podsProject.ContainsFileByRealPath(sourceFilePathInPod, 
+               UnityEditor.iOS.Xcode.PBXSourceTree.Source))
+            {
+                Log("Adding source file " + sourceFilePathInPod + " to Xcode project.", true);
+                project.AddFileToBuild(
+                    target,
+                    project.AddFile(podPathProjectPath.Value,
+                                    podPathProjectPath.Value,
+                                    UnityEditor.iOS.Xcode.PBXSourceTree.Source));
+                // Some source pods (e.g Protobuf) can include files relative to the Pod root,
+                // add include paths relative to the Pod's source files for this use case.
+                project.UpdateBuildProperty(
+                        new [] { target }, "USER_HEADER_SEARCH_PATHS",
+                        new [] { "$(SRCROOT)/" + Path.GetDirectoryName(podPathProjectPath.Value) },
+                        new string[] {});
+            } 
+            else
+            {
+                Log("Skipping adding source file " + sourceFilePathInPod + 
+                    " to Xcode project due to it is not part of the pod project", true);
+            }
         }
 
         // Each source pod library target name shares the name of the directory containing
@@ -2348,11 +2372,9 @@ public static void UpdateProjectDeps(
         }
 
         // Attempt to read per-file compile / build settings from the Pods
-        // project.
-        var podsProjectPath = GetProjectPath(podsDir, PODS_PROJECT_NAME);
-        if (File.Exists(podsProjectPath)) {
-            var podsProject = new UnityEditor.iOS.Xcode.PBXProject();
-            podsProject.ReadFromString(File.ReadAllText(podsProjectPath));
+        // project. Note that we have a valid podsProject if Pod pbxproj exists.
+        // We have a valid podsProject if Pod pbxproj exists.
+        if (podsProject != null) {
             foreach (var directory in Directory.GetDirectories(podsDir)) {
                 // Each pod will have a top level directory under the pods dir
                 // named after the pod.  Also, some pods have build targets in