update

android/app/build.gradle

@@ -2,6 +2,8 @@ plugins {
     id "com.android.application"
     id "kotlin-android"
     id "dev.flutter.flutter-gradle-plugin"
+    id "com.google.gms.google-services"
+    id "com.google.firebase.crashlytics"
 }
 
 def localProperties = new Properties()
@@ -45,7 +47,7 @@ android {
         applicationId "com.appscale.pos"
         // You can update the following values to match your application needs.
         // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
-        minSdkVersion 21
+        minSdkVersion 23
         targetSdkVersion 35
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
@@ -69,4 +71,6 @@ dependencies {
     //multiDex
     implementation 'com.android.support:multidex:1.0.3'
     implementation 'androidx.multidex:multidex:2.0.1'
+    implementation platform('com.google.firebase:firebase-bom:34.2.0')
+    implementation 'com.google.firebase:firebase-crashlytics'
 }