Version bumps and release manifest required for FIS release

Firebase.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'Firebase'
-  s.version          = '6.13.0'
+  s.version          = '6.15.0'
   s.summary          = 'Firebase for iOS (plus community support for macOS and tvOS)'
 
   s.description      = <<-DESC
@@ -95,7 +95,7 @@ Simplify your iOS development, grow your user base, and monetize more effectivel
 
   s.subspec 'Messaging' do |ss|
     ss.dependency 'Firebase/CoreOnly'
-    ss.dependency 'FirebaseMessaging', '~> 4.1.9'
+    ss.dependency 'FirebaseMessaging', '~> 4.2.0'
   end
 
   s.subspec 'Performance' do |ss|

FirebaseCore.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'FirebaseCore'
-  s.version          = '6.4.0'
+  s.version          = '6.6.0'
   s.summary          = 'Firebase Core for iOS (plus community support for macOS and tvOS)'
 
   s.description      = <<-DESC
@@ -39,7 +39,7 @@ Firebase Core includes FIRApp and FIROptions which provide central configuration
   s.pod_target_xcconfig = {
     'GCC_C_LANGUAGE_STANDARD' => 'c99',
     'GCC_PREPROCESSOR_DEFINITIONS' =>
-      'FIRCore_VERSION=' + s.version.to_s + ' Firebase_VERSION=6.13.0',
+      'FIRCore_VERSION=' + s.version.to_s + ' Firebase_VERSION=6.15.0',
     'OTHER_CFLAGS' => '-fno-autolink'
   }
   s.test_spec 'unit' do |unit_tests|

Releases/Manifests/6.15.0.json

@@ -0,0 +1,7 @@
+{
+  "Firebase":"6.15.0",
+  "FirebaseCore":"6.6.0",
+  "FirebaseMessaging":"4.2.0",
+  "FirebaseInstanceID":"4.3.0",
+  "FirebaseInstallations":"1.0.0"
+}