- gradle version upgrade

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

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Tue Apr 28 17:08:04 BST 2020
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.4-all.zip