[interactive_media_ads] Update example's minimum iOS target to 15.0 #177931
Description
The interactive_media_ads example app is failing to build in CI.
This is because its dependency GoogleInteractiveMediaAds now requires a minimum platform version of iOS 15.0, but the example app's Podfile is still set to 12.0.
Error from CI log:
The pod 'GoogleInteractiveMediaAds' required by 'interactive_media_ads' requires minimum platform version 15.0 for the iOS platform, but this target supports 12.0.
Fix: The minimum platform version in packages/interactive_media_ads/example/ios/Podfile needs to be updated from 12.0 to 15.0.