- gradle version upgrade

- migrated to AndroidX
 - migrated to Kotlin
 - Content resolver unit test added
 - Upgraded android version to 31

build.gradle

@@ -1,12 +1,16 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+    ext {
+        kotlin_version = '1.9.0'
+    }
     repositories {
         google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.1'
+        classpath 'com.android.tools.build:gradle:7.4.1'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files