change to min sdk 26, move local check to settings and add native activity

app/build.gradle

@@ -4,10 +4,10 @@ android {
     compileSdkVersion 28
     defaultConfig {
         applicationId "de.weseng.wifiweatherstation"
-        minSdkVersion 16
+        minSdkVersion 26
         targetSdkVersion 28
-        versionCode 20190302
-        versionName "2019.3.2"
+        versionCode 20190309
+        versionName "2019.3.9"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     buildTypes {
@@ -22,6 +22,7 @@ dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    implementation 'com.android.support:support-annotations:28.0.0'
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'