conf: bump target sdk version

Author: aman-singh7

android/app/build.gradle

@@ -42,7 +42,7 @@ android {
     defaultConfig {
         applicationId "in.ac.iitr.mdg.appetizer"
         minSdkVersion 21
-        targetSdkVersion 29
+        targetSdkVersion 30
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"