[Android][Kotlin] fixed build after decomission of jcenter and gradle update (#7840)

* [Android] fixed build after decomission of jcenter

JCenter[1] has been removed and now is failing android build. This
change updates the configuration to remove this and few other warnings.

1 - https://developer.android.com/studio/build/jcenter-migration

* [Kotlin] fix build for latest gradle version 8.0.1

---------

Co-authored-by: Derek Bailey <derekbailey@google.com>

kotlin/build.gradle.kts

@@ -1,7 +1,3 @@
-plugins {
-  id("com.diffplug.spotless") version "6.3.0"
-}
-
 group = "com.google.flatbuffers"
 version = "2.0.0-SNAPSHOT"
 
@@ -12,7 +8,10 @@ buildscript {
     mavenCentral()
   }
   dependencies {
-    classpath(libs.bundles.plugins)
+    classpath(libs.plugin.kotlin.gradle)
+    classpath(libs.plugin.kotlinx.benchmark)
+    classpath(libs.plugin.jmhreport)
+    classpath(libs.plugin.download)
   }
 }
 
@@ -22,21 +21,3 @@ allprojects {
     mavenCentral()
   }
 }
-
-// plugin used to enforce code style
-spotless {
-  val klintConfig = mapOf("indent_size" to "2", "continuation_indent_size" to "2")
-  kotlin {
-    target("**/*.kt")
-    ktlint("0.40.0").userData(klintConfig)
-    trimTrailingWhitespace()
-    indentWithSpaces()
-    endWithNewline()
-    licenseHeaderFile("$rootDir/spotless/spotless.kt").updateYearWithLatest(false)
-    targetExclude("**/spotless.kt", "**/build/**")
-  }
-  kotlinGradle {
-    target("*.gradle.kts")
-    ktlint().userData(klintConfig)
-  }
-}