LevelPlay ahead on Google Play SDK version conflicting pod install

[MartinGonzalez]

[REQUIRED] Step 1: Describe your environment

• Unity version: 6000.3.1f1
• Google Mobile Ads Unity plugin version: 10.6.0
• Plugin installation method: Unity package manager
• Platform: iOS
• Platform OS version: -
• Any specific devices issue occurs on: none
• Mediation ad networks used, and their versions: LevelPlay

[REQUIRED] Step 2: Describe the problem

LevelPlay Admob adapter is ahead on Google-Mobile-Ads-SDK using v12.14.0 where latest package of google-mobile-ads uses 12.12.0 generating a conflict pod dependencies which is completely annoying.

[!] CocoaPods could not find compatible versions for pod "Google-Mobile-Ads-SDK":
  In Podfile:
    Google-Mobile-Ads-SDK (~> 12.12.0)

    IronSourceAdMobAdapter (= 5.4.0.0) was resolved to 5.4.0.0, which depends on
      Google-Mobile-Ads-SDK (= 12.14.0)

Specs satisfying the `Google-Mobile-Ads-SDK (~> 12.12.0), Google-Mobile-Ads-SDK (= 12.14.0)` dependency were found, but they required a higher minimum deployment target.

Steps to reproduce:

1. Install LevelPlay
2. Add AdmobAdapte
3. Add Google Play dependency
4. build for ios
5. try to run pod install