[dependabot]: Bump the gradle-plugin group across 3 directories with 1 update

Bumps the gradle-plugin group with 1 update in the /packages/interactive_media_ads/android directory: [org.jetbrains.kotlin:kotlin-gradle-plugin](https://github.com/JetBrains/kotlin).
Bumps the gradle-plugin group with 1 update in the /packages/shared_preferences/shared_preferences_android/android directory: [org.jetbrains.kotlin:kotlin-gradle-plugin](https://github.com/JetBrains/kotlin).
Bumps the gradle-plugin group with 1 update in the /packages/webview_flutter/webview_flutter_android/android directory: [org.jetbrains.kotlin:kotlin-gradle-plugin](https://github.com/JetBrains/kotlin).


Updates `org.jetbrains.kotlin:kotlin-gradle-plugin` from 1.9.10 to 2.1.0
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.10...v2.1.0)

Updates `org.jetbrains.kotlin:kotlin-gradle-plugin` from 1.7.10 to 2.1.0
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.10...v2.1.0)

Updates `org.jetbrains.kotlin:kotlin-gradle-plugin` from 1.9.10 to 2.1.0
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.9.10...v2.1.0)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: gradle-plugin
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: gradle-plugin
- dependency-name: org.jetbrains.kotlin:kotlin-gradle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: gradle-plugin
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

packages/interactive_media_ads/android/build.gradle

@@ -2,7 +2,7 @@ group 'dev.flutter.packages.interactive_media_ads'
 version '1.0-SNAPSHOT'
 
 buildscript {
-    ext.kotlin_version = '1.9.10'
+    ext.kotlin_version = '2.1.0'
     repositories {
         google()
         mavenCentral()

packages/shared_preferences/shared_preferences_android/android/build.gradle

@@ -2,7 +2,7 @@ group 'io.flutter.plugins.sharedpreferences'
 version '1.0-SNAPSHOT'
 
 buildscript {
-    ext.kotlin_version = '1.7.10'
+    ext.kotlin_version = '2.1.0'
     repositories {
         google()
         mavenCentral()

packages/webview_flutter/webview_flutter_android/android/build.gradle

@@ -2,7 +2,7 @@ group 'io.flutter.plugins.webviewflutter'
 version '1.0-SNAPSHOT'
 
 buildscript {
-    ext.kotlin_version = '1.9.10'
+    ext.kotlin_version = '2.1.0'
     repositories {
         google()
         mavenCentral()