firebase-ios-sdk

FIAM Consolidation (#4705)

* Move display SDK source and resources into FIAM SDK

* Change files prefixed with FID to be prefixed FIRIAM

* Restructure example apps in firebase-ios-sdk directory

* Fix directory structure for FIAM

* Move proto files into base directory

* Fix up proto files

* Move unit test files to Firebase/InAppMessaging/Tests

* Move FIRIAMSDKModeManagerTests and require app host in podspec

* Move sample apps to tests folder

* Add empty repo for FIAMDisplay that generates a warning

* Fix up functional tests app

* Fix up default UI test app

* Re-generate protos

* Add warning to remove display pod

* Remove display podspec from .travis.yml

* Remove trailing whitespace

* Fix import in test app

* Add changes to point to the default test app

* Wrap iOS version conditionals

* Add line in podspec about deprecation

* Delete whitespace in podspec

* Delete pods section in project file

* Update changelog with consolidation info

* Fix indentation in podspecs

* Fix some import issues

* Fix indent on FirebaseInAppMessaging.podspec

* Delete FirebaseInAppMessagingDisplay, update podfile for external test app

* Update podfiles, bump iOS min version to 9, remove iOS 9 checks in FIRIAMActionUrlFollowerTests

*  Add line in CHANGELOG referencing deletion of display sdk pod

* Remove unused podfile

* Update min version on Podfiles to iOS 9

* Add back FirebaseInAppMessagingDisplay.h

* Add iOS support message to CHANGELOG.md

* Wrap necessary deprecated iOS 9 call