firebase-ios-sdk: Application freezes only on first analytics logEvent call after fresh application install

[REQUIRED] Step 2: Describe your environment

• Xcode version: 10.1
• Firebase SDK version: 6.0.0 (latest)
• Firebase Component: Analytics
• Component version: 6.0.0

[REQUIRED] Step 3: Describe the problem

We are trying to configure our application to use Firebase Analytics and GoogleTagManager to report analytics events.

After a fresh install of the application, when trying to log a custom event, the application hangs. In subsequent launches of the application, the events are always logged without problem.

Deleting the app and installing fresh will often result in the first custom event logged to firebase to cause an app freeze.

Steps to reproduce:

1. Configure your application to use Firebase Analytics along with Google Tag Manager. Install them both via cocoapods by adding the following to your podfile.

use_frameworks!
platform :ios, '12.0'

def import_pods
    pod 'Firebase/Analytics'
    pod 'GoogleTagManager'
end

1. execute pod install to setup project
2. Add Firebase supplied GoogleService-Info.plist to the Xcode project
3. Download and add the configured GoogleTagManager container to the Xcode project
4. Initialize Firebase in application AppDelegate via call to FirebaseApp.configure()
5. Perform call to log custom firebase analytics event by Analytics.logEvent(_ name: String, parameters: [String : Any]?)

After first logEvent call, application will hang but will not crash. When running via simulator the following output can be scene with debug enabled (-FIRDebugEnabled)

2019-05-23 14:57:05.049719-0400 AppName[20939:1116742] [BoringSSL] nw_protocol_boringssl_input_finished(1543) [C4.1:2][0x7fb8b3d39080] Peer disconnected during the middle of a handshake. Sending errSSLClosedNoNotify(-9816) alert
2019-05-23 14:57:05.058921-0400 AppName[20939:1116742] TIC TCP Conn Failed [4:0x600000ea5800]: 3:-9816 Err(-9816)
2019-05-23 14:57:05.060957-0400 AppName[20939:1116742] NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9816)
2019-05-23 14:57:05.061082-0400 AppName[20939:1116742] Task <0F5152F7-86F3-4356-A4E0-11337A42BF3F>.<1> HTTP load failed (error code: -1200 [3:-9816])
2019-05-23 14:57:05.061274-0400 AppName[20939:1116809] Task <0F5152F7-86F3-4356-A4E0-11337A42BF3F>.<1> finished with error - code: -1200

When running on a physical device, the same app freeze is seen but the boringssl logs are not logged.