Updated required Android SDK to API 26, to match Google's new App Store requirements

android-project/app/build.gradle

@@ -8,14 +8,14 @@ else {
 }
 
 android {
-    compileSdkVersion 19
+    compileSdkVersion 26
     buildToolsVersion "26.0.1"
     defaultConfig {
         if (buildAsApplication) {
             applicationId "org.libsdl.app"
         }
         minSdkVersion 14
-        targetSdkVersion 19
+        targetSdkVersion 26
         versionCode 1
         versionName "1.0"
         externalNativeBuild {

docs/README-android.md

@@ -14,10 +14,10 @@ supported, but you can use the "android-project-ant" directory as a template.
  Requirements
 ================================================================================
 
-Android SDK (version 19 or later)
+Android SDK (version 26 or later)
 https://developer.android.com/sdk/index.html
 
-Android NDK r10e or later
+Android NDK r15c or later
 https://developer.android.com/tools/sdk/ndk/index.html
 
 Minimum API level supported by SDL: 14 (Android 4.0.1)