Update GDT versions and deps (#5713)

* Update GoogleDataTransport.podspec

* Update GoogleDataTransportCCTSupport.podspec

* Update FirebaseCrashlytics.podspec

* Update CHANGELOG.md

* Update GoogleDataTransportCCTSupport.podspec

* Update FirebaseCrashlytics.podspec

GoogleDataTransport.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'GoogleDataTransport'
-  s.version          = '6.2.0'
+  s.version          = '6.2.1'
   s.summary          = 'Google iOS SDK data transport.'
 
   s.description      = <<-DESC

GoogleDataTransport/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# v6.2.1
 - Stopped GDTCORUploadCoordinator from blocking main thread. (#5707, #5708)
 
 # v6.2.0