Update default compile and target SDK versions to 28

Author: darind

test-app/app/build.gradle

@@ -72,10 +72,10 @@ version of the {N} CLI install a previous version of the runtime package - 'tns
 project.ext.extractedDependenciesDir = "${project.buildDir}/exploded-dependencies"
 def nativescriptDependencies = new JsonSlurper().parseText(dependenciesJson.text)
 
-def computeCompileSdkVersion = { -> project.hasProperty("compileSdk") ? compileSdk : 26 }
-def computeTargetSdkVersion = { -> project.hasProperty("targetSdk") ? targetSdk : 26 }
+def computeCompileSdkVersion = { -> project.hasProperty("compileSdk") ? compileSdk : 28 }
+def computeTargetSdkVersion = { -> project.hasProperty("targetSdk") ? targetSdk : 28 }
 def computeBuildToolsVersion = { ->
-    project.hasProperty("buildToolsVersion") ? buildToolsVersion : "28.0.2"
+    project.hasProperty("buildToolsVersion") ? buildToolsVersion : "28.0.3"
 }
 
 project.ext.selectedBuildType = project.hasProperty("release") ? "release" : "debug"

test-app/runtime/build.gradle

@@ -20,7 +20,7 @@ if (useCCache) {
     println "Use CCache build triggered."
 }
 
-project.ext._buildToolsVersion = "28.0.2"
+project.ext._buildToolsVersion = "28.0.3"
 
 android {
     sourceSets {