migrate to built-in gradle dependency verification

closes #693

app/build.gradle

@@ -2,8 +2,6 @@ apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
 apply plugin: 'kotlin-android-extensions'
 apply plugin: 'kotlin-kapt'
-apply plugin: 'witness'
-apply from: 'witness.gradle'
 
 android {
 

build.gradle

@@ -14,7 +14,6 @@ buildscript {
 	dependencies {
 		classpath 'com.android.tools.build:gradle:4.1.3'
 		classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion"
-		classpath files('app/libs/gradle-witness.jar')
 	}
 
 }

update-dependency-pinning.sh

@@ -1,7 +1,9 @@
 #!/bin/bash
 
-WITNESS=app/witness.gradle
+# this will just append new checksums and not remove unnecessary ones
 
-echo "" > $WITNESS
-./gradlew -q calculateChecksums | grep -Ev "^(Skipping|Verifying)" | grep -Ev "files-2.1:|caches:transforms-3:|:build-tools:core-lambda-stubs.jar:|:platforms:android.jar:|-linux.jar:" > $WITNESS
+# to clean up the file, remove ./gradle/verification-metadata.xml,
+# run the command below and manually (re-)add checksums for missing operating systems windows, osx or linux for aapt2
+# checksums can be computed after downloading the respective jars of https://maven.google.com/web/index.html?q=aapt2#com.android.tools.build:aapt2
 
+./gradlew --write-verification-metadata sha256 build