android: update gradle and build tools versions

Also disable erroring out on lint failure for now.

webrtc/android/app/build.gradle

@@ -2,7 +2,6 @@ apply plugin: 'com.android.application'
 
 android {
     compileSdkVersion 23
-    buildToolsVersion "26.0.2"
 
     defaultConfig {
         applicationId "org.freedesktop.gstreamer.webrtc"
@@ -46,6 +45,10 @@ android {
             path 'src/main/jni/Android.mk'
         }
     }
+
+    lintOptions {
+        abortOnError false
+    }
 }
 
 afterEvaluate {

webrtc/android/build.gradle

@@ -6,10 +6,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.1'
-
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
+        classpath 'com.android.tools.build:gradle:3.2.0'
     }
 }
 
@@ -23,3 +20,14 @@ allprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+ext {
+	supportLibVersion = '27.1.1'  // variable that can be referenced to keep support libs consistent
+	commonLibVersion= '2.12.4'
+	versionBuildTool = '28.0.3'
+	versionCompiler = 28
+	versionTarget = 27
+	versionNameString = '1.0.0'
+	javaSourceCompatibility = JavaVersion.VERSION_1_8
+	javaTargetCompatibility = JavaVersion.VERSION_1_8
+}