Updated samples to gma 2.4.0 (#806)

Co-authored-by: Justin Malandruccolo <jmalandruccolo@google.com>

Author: malandr2

samples/admob/adaptive_banner_example/pubspec.yaml

@@ -36,7 +36,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads: ^2.1.0
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test:

samples/admob/banner_example/pubspec.yaml

@@ -36,7 +36,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads: ^2.3.0
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test:

samples/admob/interstitial_example/pubspec.yaml

@@ -36,7 +36,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads: ^2.2.0
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test:

samples/admob/native_platform_example/pubspec.yaml

@@ -35,7 +35,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads: ^2.3.0
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test:

samples/admob/native_template_example/pubspec.yaml

@@ -35,10 +35,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads:
-    git:
-      url: https://github.com/googleads/googleads-mobile-flutter.git
-      path: packages/google_mobile_ads
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test:

samples/admob/rewarded_example/pubspec.yaml

@@ -36,7 +36,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads: ^2.2.0
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test:

samples/admob/rewarded_interstitial_example/pubspec.yaml

@@ -36,7 +36,7 @@ dependencies:
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
-  google_mobile_ads: ^2.3.0
+  google_mobile_ads: ^2.4.0
 
 dev_dependencies:
   flutter_test: