Update deps to remove all usage of Bintray. (google#422)

Fixes google#401

build.gradle

@@ -1,21 +1,18 @@
 buildscript {
     repositories {
         gradlePluginPortal()
-        jcenter()
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
-        classpath 'gradle.plugin.com.github.sherter.google-java-format:google-java-format-gradle-plugin:0.6'
-        // NOTE: 0.7 or newer will require upgrading to a newer Android gradle plugin:
-        // https://github.com/tbroyer/gradle-errorprone-plugin/commit/65b1026ebeae1b7ed8c28578c7f6eea512c16bea
-        classpath 'net.ltgt.errorprone:net.ltgt.errorprone.gradle.plugin:0.6.1'
+        classpath 'com.android.tools.build:gradle:4.2.2'
+        classpath 'gradle.plugin.com.github.sherter.google-java-format:google-java-format-gradle-plugin:0.9'
+        classpath 'net.ltgt.errorprone:net.ltgt.errorprone.gradle.plugin:2.0.2'
     }
 }
 
 allprojects {
     repositories {
-        jcenter()
+        mavenCentral()
         google()
     }
 }
@@ -47,7 +44,7 @@ subprojects {
         useLibrary 'org.apache.http.legacy'
 
         compileSdkVersion 28
-        buildToolsVersion = '28.0.3'
+        buildToolsVersion = '30.0.3'
 
         defaultConfig {
             minSdkVersion 8

gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-all.zip

publish.gradle

@@ -12,7 +12,7 @@ task javadoc(type: Javadoc) {
 
 afterEvaluate {
     javadoc.classpath += files(android.libraryVariants.collect { variant ->
-        variant.getJavaCompile().classpath.files
+        variant.getJavaCompileProvider().get().classpath.files
     })
 }