Missed gradle changes

app/build.gradle

@@ -156,7 +156,6 @@ configurations.all {
 dependencies {
     coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.5'
 
-    def appcompat_version = "1.2.0"
     def nav_version = '2.3.5'
     def exoplayer_version = '2.13.3'
 
@@ -175,7 +174,6 @@ dependencies {
     implementation "androidx.preference:preference:1.1.1"
     implementation "androidx.work:work-runtime:2.5.0"
     implementation 'androidx.palette:palette:1.0.0'
-    implementation "androidx.lifecycle:lifecycle-extensions:2.2.0"
 
     implementation 'com.google.guava:guava:27.0.1-android'