improvement : removed required kotlin dependency (#125002)

This PR removed the non-necessary required Koltin dependency. This is because the Kotlin Gradle adds the dependency on the standard library automatically. 

Fixes #98212

*If you had to change anything in the [flutter/tests] repo, include a link to the migration guide as per the [breaking change policy]. *

packages/flutter_tools/templates/app_shared/android-kotlin.tmpl/app/build.gradle.tmpl

@@ -64,6 +64,4 @@ flutter {
     source '../..'
 }
 
-dependencies {
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-}
+dependencies {}