Fixed build warnings introduced with Xcode 12.5 (#7432)

Author: paulb777

FirebaseRemoteConfig/CHANGELOG.md

@@ -1,3 +1,6 @@
+# v7.6.0
+- [fixed] Fixed build warnings introduced with Xcode 12.5. (#7432)
+
 # v7.5.0
 - [fixed] Fixed bug that was incorrectly flagging ABT experiment payloads as invalid. (#7184)
 - [changed] Standardize support for Firebase products that integrate with Remote Config. (#7094)

FirebaseRemoteConfig/Sources/RCNDevice.m

@@ -59,7 +59,7 @@ RCNDeviceModel FIRRemoteConfigDeviceSubtype() {
   return [[[NSLocale currentLocale] objectForKey:NSLocaleCountryCode] lowercaseString];
 }
 
-NSDictionary<NSString *, NSArray *> *FIRRemoteConfigFirebaseLocaleMap() {
+NSDictionary<NSString *, NSArray *> *FIRRemoteConfigFirebaseLocaleMap(void) {
   return @{
     // Albanian
     @"sq" : @[ @"sq_AL" ],
@@ -179,15 +179,15 @@ RCNDeviceModel FIRRemoteConfigDeviceSubtype() {
   };
 }
 
-NSArray<NSString *> *FIRRemoteConfigAppManagerLocales() {
+NSArray<NSString *> *FIRRemoteConfigAppManagerLocales(void) {
   NSMutableArray *locales = [NSMutableArray array];
   NSDictionary<NSString *, NSArray *> *localesMap = FIRRemoteConfigFirebaseLocaleMap();
   for (NSString *key in localesMap) {
     [locales addObjectsFromArray:localesMap[key]];
   }
   return locales;
 }
-NSString *FIRRemoteConfigDeviceLocale() {
+NSString *FIRRemoteConfigDeviceLocale(void) {
   NSArray<NSString *> *locales = FIRRemoteConfigAppManagerLocales();
   NSArray<NSString *> *preferredLocalizations =
       [NSBundle preferredLocalizationsFromArray:locales
@@ -197,7 +197,7 @@ RCNDeviceModel FIRRemoteConfigDeviceSubtype() {
   return legalDocsLanguage ? legalDocsLanguage : @"en";
 }
 
-NSString *FIRRemoteConfigTimezone() {
+NSString *FIRRemoteConfigTimezone(void) {
   NSTimeZone *timezone = [NSTimeZone systemTimeZone];
   return timezone.name;
 }