change minimum supported Android version to 4.2

Signed-off-by: Andy Scherzinger <info@andy-scherzinger.de>

build.gradle

@@ -129,7 +129,7 @@ android {
     compileSdkVersion 29
 
     defaultConfig {
-        minSdkVersion 16
+        minSdkVersion 17
         targetSdkVersion 29
 
         // arguments to be passed to functional tests