Remove pointless build tools and use latest

Author: hannesa2

BasicSample/app/build.gradle

@@ -18,7 +18,6 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion build_versions.compile_sdk
-    buildToolsVersion build_versions.build_tools
 
     defaultConfig {
         applicationId 'com.example.android.persistence'

LiveDataSample/app/build.gradle

@@ -21,7 +21,7 @@ apply plugin: 'kotlin-android-extensions'
 
 android {
     compileSdkVersion build_versions.compile_sdk
-    buildToolsVersion build_versions.build_tools
+
     defaultConfig {
         applicationId "com.android.example.livedata"
         minSdkVersion build_versions.min_sdk

LiveDataSample/versions.gradle

@@ -69,7 +69,6 @@ def build_versions = [:]
 build_versions.min_sdk = 14
 build_versions.compile_sdk = 29
 build_versions.target_sdk = 29
-build_versions.build_tools = "29.0.3"
 ext.build_versions = build_versions
 
 def deps = [:]

WorkManagerMultiprocessSample/app/build.gradle

@@ -21,7 +21,6 @@ plugins {
 
 android {
     compileSdkVersion 30
-    buildToolsVersion "30.0.3"
 
     defaultConfig {
         applicationId "com.example.background.multiprocess"