Upgrade Gradle and AGP (8.9 / 8.6)

Upgrade Gradle to 8.9 and AGP to 8.6 (in conjunction with upgrading
Android Studio to 2024.1.2).

build.gradle

@@ -28,7 +28,7 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:8.5.2'
+        classpath 'com.android.tools.build:gradle:8.6.0'
         classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.7.20'
     }
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,9 +1,9 @@
 #Sun Jan 09 23:54:26 EST 2022
 distributionBase=GRADLE_USER_HOME
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.9-bin.zip
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 # https://gradle.org/release-checksums/
 # https://commonsware.com/blog/2023/01/28/applying-distributionSha256Sum-gradle-android-studio.html
-distributionSha256Sum=544c35d6bd849ae8a5ed0bcea39ba677dc40f49df7d1835561582da2009b961d
+distributionSha256Sum=d725d707bfabd4dfdc958c624003b3c80accc03f7037b5122c4b1d0ef15cecab