* Add activated experiment metadata and payload keys to experiments table
* Call updateActivatedExperiments in activation method
* Update key name for experiments table
* Update test to include activation call
* Update DB manager for Active experiments payload and metadata
* Fix metadata naming
* add comment
* Don't save experiments metadata b/c it isn't required to diff experiments
* Add extra assertion for test
* Address PR comments
* Insert and load config metadata by namespace
* Deprecate existing metadata table name
* Update tests
* Fix delete method and update naming
* Add test for writing metadate for multiple namespaces
* Add RC test app.
* Add private header files to podspec used by 2P.
* Rename FIRRemoteConfig_Internal.h to FIRRemoteConfig_Private.h.
* Fix style.
* Add copyright notice.
* Fix relative path to RCNConfigSettings for tests.
* Fix style.
* Rename to FIRRemoteConfig_Private.h for unit tests.
* Rename to coorect relative path.