l1-s11 up minsdk of android up (to mpp library level)

Author: Alex009

android-app/build.gradle

@@ -8,7 +8,7 @@ android {
     compileSdkVersion 28
     defaultConfig {
         applicationId "com.icerockdev.android_app"
-        minSdkVersion 19
+        minSdkVersion 21
         targetSdkVersion 28
         versionCode 1
         versionName "1.0"