Update iOS deployment target to 16.0 and GoogleMaps SDK to 10.0

What

• Updated iOS minimum deployment target from 15.0 to 16.0 across all project configurations
• Updated GoogleMaps dependency from ~> 9.0 to ~> 10.0 in podspec
• Updated sample app projects (ObjCDemoApp and SwiftDemoApp) deployment targets to 16.0
• Updated Podfile.template to reflect new versions (iOS 16.0, GoogleMaps 10.0.0)

Why

This PR addresses the GoogleMaps SDK version compatibility raised in #545 where the community requested updating the GoogleMaps SDK dependency to v10.0.0.

Issues Resolved:

1. Version Conflict: GoogleMaps 10.0.0 requires iOS 16.0 minimum, but the project was configured for iOS 15.0, causing CocoaPods installation failures with the error:

   "The package product 'GoogleMaps' requires minimum platform version 16.0 for the iOS platform, but this target supports 15.0"
   

2. Dependency Mismatch: The Package.swift was already using GoogleMaps 10.0.0, but the podspec was still referencing ~> 9.0, creating inconsistency between Swift Package Manager and CocoaPods configurations

3. Sample App Compatibility: Demo applications had mixed deployment targets (14.0, 15.0) that were incompatible with the new GoogleMaps SDK requirements

Files Changed

• Google-Maps-iOS-Utils.podspec - Updated iOS platform and GoogleMaps dependency
• Podfile.template - Updated iOS platform and GoogleMaps version
• samples/ObjCDemoApp/ObjCDemoApp.xcodeproj/project.pbxproj - Updated deployment targets
• samples/SwiftDemoApp/SwiftDemoApp.xcodeproj/project.pbxproj - Updated deployment targets

Testing

• Verified pod install runs successfully in sample apps
• Confirmed all deployment targets are consistently set to 16.0
• Validated Package.swift and podspec dependency alignment
• Verified running all the tests

Fixes #545