mediation typo fixes (#1031)

Fixes "medation" typos in GMA documentation and code.

Author: DellaBitta

gma/src/android/ad_request_converter.cc

@@ -54,7 +54,7 @@ jobject GetJavaAdRequestFromCPPAdRequest(const AdRequest& request,
 
   // Network Extras.
   // The map associates class names of mediation adapters with a
-  // key value pairs, the extras, to send to those medation adapters.
+  // key value pairs, the extras, to send to those mediation adapters.
   // e.g. Mediation_Map < class name, Extras_Map < key, value > >
   const std::map<std::string, std::map<std::string, std::string>>& extras =
       request.extras();

gma/src/android/response_info_android.cc

@@ -64,13 +64,13 @@ ResponseInfo::ResponseInfo(const ResponseInfoInternal& response_info_internal) {
   }
 
   // The Mediation Adapter class name.
-  const jobject j_medation_adapter_classname = env->CallObjectMethod(
+  const jobject j_mediation_adapter_classname = env->CallObjectMethod(
       j_response_info,
       response_info::GetMethodId(response_info::kGetMediationAdapterClassName));
-  if (j_medation_adapter_classname != nullptr) {
+  if (j_mediation_adapter_classname != nullptr) {
     mediation_adapter_class_name_ =
-        util::JStringToString(env, j_medation_adapter_classname);
-    env->DeleteLocalRef(j_medation_adapter_classname);
+        util::JStringToString(env, j_mediation_adapter_classname);
+    env->DeleteLocalRef(j_mediation_adapter_classname);
   }
 
   // The Response ID for this adapter response.

gma/src/include/firebase/gma/types.h

@@ -657,15 +657,15 @@ class AdRequest {
     return neighboring_content_urls_;
   }
 
-  /// Add a network extra for the associated ad medation adapter.
+  /// Add a network extra for the associated ad mediation adapter.
   ///
-  /// Appends an extra to the corresponding list of extras for the ad medation
-  /// adapter. Each ad medation adapter can have multiple extra strings.
+  /// Appends an extra to the corresponding list of extras for the ad mediation
+  /// adapter. Each ad mediation adapter can have multiple extra strings.
   ///
-  /// @param[in] adapter_class_name the class name of the ad medation adapter
+  /// @param[in] adapter_class_name the class name of the ad mediation adapter
   /// for which to add the extra.
   /// @param[in] extra_key a key which will be passed to the corresponding ad
-  /// medation adapter.
+  /// mediation adapter.
   /// @param[in] extra_value the value associated with extra_key.
   void add_extra(const char* adapter_class_name, const char* extra_key,
                  const char* extra_value);

gma/src/ios/response_info_ios.mm

@@ -59,7 +59,7 @@
   }
 
   NSString *to_string = [[NSString alloc]initWithFormat:@"ResponseInfo "
-    "response_id: %@, medation_adapter_classname : %@, "
+    "response_id: %@, mediation_adapter_classname : %@, "
     "adapter_response_info: %@", 
     response_info_internal.gad_response_info.responseIdentifier,
     response_info_internal.gad_response_info.adNetworkClassName,