Add FID into real-time RC requests (#11485)

* Set FID in realtime request

* Update request method naming

* Update test

* Fix tests

* Fix test

Author: qdpham13

FirebaseRemoteConfig/Sources/RCNConfigRealtime.m

@@ -298,7 +298,7 @@ - (void)refreshInstallationsTokenWithCompletionHandler:
   [installations authTokenWithCompletion:installationsTokenHandler];
 }
 
-- (void)setRequestBody {
+- (NSData *)createRequestBody {
   [self refreshInstallationsTokenWithCompletionHandler:^(FIRRemoteConfigFetchStatus status,
                                                          NSError *_Nullable error) {
     if (status != FIRRemoteConfigFetchStatusSuccess) {
@@ -315,14 +315,13 @@ - (void)setRequestBody {
   NSString *namespace = [_namespace substringToIndex:[_namespace rangeOfString:@":"].location];
   NSString *postBody = [NSString
       stringWithFormat:@"{project:'%@', namespace:'%@', lastKnownVersionNumber:'%@', appId:'%@', "
-                       @"sdkVersion:'%@'}",
+                       @"sdkVersion:'%@', appInstanceId:'%@'}",
                        [self->_options GCMSenderID], namespace, _configFetch.templateVersionNumber,
-                       _options.googleAppID, FIRRemoteConfigPodVersion()];
+                       _options.googleAppID, FIRRemoteConfigPodVersion(),
+                       _settings.configInstallationsIdentifier];
   NSData *postData = [postBody dataUsingEncoding:NSUTF8StringEncoding];
   NSError *compressionError;
-  NSData *compressedContent = [NSData gul_dataByGzippingData:postData error:&compressionError];
-
-  [_request setHTTPBody:compressedContent];
+  return [NSData gul_dataByGzippingData:postData error:&compressionError];
 }
 
 /// Creates request.
@@ -665,7 +664,8 @@ - (void)beginRealtimeStream {
 
     if (canMakeConnection) {
       strongSelf->_isRequestInProgress = true;
-      [strongSelf setRequestBody];
+      NSData *compressedContent = [strongSelf createRequestBody];
+      [strongSelf->_request setHTTPBody:compressedContent];
       strongSelf->_dataTask = [strongSelf->_session dataTaskWithRequest:strongSelf->_request];
       [strongSelf->_dataTask resume];
     }

FirebaseRemoteConfig/Tests/Unit/RCNRemoteConfigTest.m

@@ -72,6 +72,7 @@ - (void)scheduleFetch:(NSInteger)remainingAttempts targetVersion:(NSInteger)targ
 - (void)autoFetch:(NSInteger)remainingAttempts targetVersion:(NSInteger)targetVersion;
 - (void)beginRealtimeStream;
 - (void)pauseRealtimeStream;
+- (NSData *)createRequestBody;
 
 - (FIRConfigUpdateListenerRegistration *_Nonnull)addConfigUpdateListener:
     (RCNConfigUpdateCompletion _Nonnull)listener;
@@ -243,6 +244,7 @@ - (void)setUp {
                                                                settings:_settings
                                                               namespace:_fullyQualifiedNamespace
                                                                 options:currentOptions]);
+    _settings.configInstallationsIdentifier = @"iid";
 
     OCMStubRecorder *mock = OCMStub([_configFetch[i] fetchConfigWithExpirationDuration:0
                                                                      completionHandler:OCMOCK_ANY]);
@@ -1765,6 +1767,21 @@ - (void)testRealtimeDisabled {
   }
 }
 
+- (void)testRealtimeStreamRequestBody {
+  NSError *error;
+  NSData *requestBody = [_configRealtime[0] createRequestBody];
+  NSData *uncompressedRequest = [NSData gul_dataByInflatingGzippedData:requestBody error:&error];
+  NSString *strData = [[NSString alloc] initWithData:uncompressedRequest
+                                            encoding:NSUTF8StringEncoding];
+
+  XCTAssertTrue([strData containsString:@"project:'correct_gcm_sender_id'"]);
+  XCTAssertTrue([strData containsString:@"namespace:'firebase'"]);
+  XCTAssertTrue([strData containsString:@"lastKnownVersionNumber:'0'"]);
+  XCTAssertTrue([strData containsString:@"appId:'1:123:ios:123abc'"]);
+  XCTAssertTrue([strData containsString:@"sdkVersion:"]);
+  XCTAssertTrue([strData containsString:@"appInstanceId:'iid'"]);
+}
+
 #pragma mark - Test Helpers
 
 - (FIROptions *)firstAppOptions {