Update CompileSdkVersion & targetSdkVersion to last version 28 (Pie)

And update support library to version 28

Sample/app/build.gradle

@@ -1,13 +1,13 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 22
-    buildToolsVersion '27.0.3'
+    compileSdkVersion 28
+    buildToolsVersion '28.0.3'
 
     defaultConfig {
         applicationId "com.microsoft.projectoxford.faceapisample"
         minSdkVersion 22
-        targetSdkVersion 22
+        targetSdkVersion 28
         versionCode 1
         versionName "1.0"
     }
@@ -27,6 +27,6 @@ dependencies {
 
     // Use the following line to include client library for Face API from Maven Central Repository
     implementation 'com.microsoft.projectoxford:face:1.4.3'
-    implementation 'com.android.support:appcompat-v7:22.1.0'
+    implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.google.code.gson:gson:2.8.2'
 }