fix build issue and warning

Author: jdvp

gradle.properties

@@ -15,7 +15,5 @@ org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
 # Android operating system, and which are packaged with your app"s APK
 # https://developer.android.com/topic/libraries/support-library/androidx-rn
 android.useAndroidX=true
-# Automatically convert third-party libraries to use AndroidX
-android.enableJetifier=true
 # Kotlin code style for this project: "official" or "obsolete":
 kotlin.code.style=official

libtestingexample/build.gradle

@@ -1,6 +1,5 @@
 plugins {
     id "com.android.library"
-    id "kotlin-android"
 }
 
 java {