Update versions for Release 6.12.0 - Firestore

FirebaseFirestore.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'FirebaseFirestore'
-  s.version          = '1.6.2'
+  s.version          = '1.7.0'
   s.summary          = 'Google Cloud Firestore for iOS'
 
   s.description      = <<-DESC

Releases/Manifests/6.12.0.json

@@ -3,7 +3,7 @@
   "FirebaseAuth":"6.4.0",
   "FirebaseCore":"6.3.2",
   "FirebaseDatabase":"6.1.2",
-  "FirebaseFirestore":"1.6.2",
+  "FirebaseFirestore":"1.7.0",
   "FirebaseInstanceID":"4.2.7",
   "FirebaseMessaging":"4.1.8",
   "FirebaseRemoteConfig":"4.4.4"