Update the Swift Package version automatically (#1428)

* Update the Swift Package version automatically

* Update update_versions.py

Author: a-maurice

scripts/update_versions.py

@@ -178,16 +178,21 @@ def update_android_deps():
 def update_unity_version(unity_sdk_version):
   version_cmake_path = os.path.join(os.getcwd(), "cmake", "firebase_unity_version.cmake")
   replacement = ""
+  podversion = get_ios_pod_version_from_cpp()
+  print(podversion)
   with open(version_cmake_path, "r") as f:
     datafile = f.readlines()
     for line in datafile:
       if "FIREBASE_UNITY_SDK_VERSION" in line:
         newline = "set(FIREBASE_UNITY_SDK_VERSION \"" + unity_sdk_version + "\""
         replacement = replacement + newline + "\n"
-      elif "FIREBASE_IOS_POD_VERSION" in line:
-        podversion = get_ios_pod_version_from_cpp()
+      elif podversion and "FIREBASE_IOS_POD_VERSION" in line:
         newline = "set(FIREBASE_IOS_POD_VERSION \"" + podversion + "\""
         replacement = replacement + newline + "\n"
+      elif podversion and "FIREBASE_SPM_VERSION" in line:
+        # Reuse the Cocoapod version number, as they are typically the same
+        newline = "set(FIREBASE_SPM_VERSION \"" + podversion + "\""
+        replacement = replacement + newline + "\n"
       elif "FIREBASE_UNITY_JAR_RESOLVER_VERSION" in line:
         jar_version = get_latest_repo_tag('googlesamples/unity-jar-resolver')
         jar_version = jar_version.lstrip("v") # jar resolver need to strip "v" from the tag