adding push notifications for android

app/mobile/android/app/build.gradle

@@ -1,4 +1,5 @@
 apply plugin: "com.android.application"
+apply plugin: 'com.google.gms.google-services'
 
 import com.android.build.OutputFile
 import org.apache.tools.ant.taskdefs.condition.Os

app/mobile/android/build.gradle

@@ -29,13 +29,29 @@ buildscript {
         classpath('com.android.tools.build:gradle:7.1.1')
         classpath('com.facebook.react:react-native-gradle-plugin')
         classpath('de.undercouch:gradle-download-task:5.0.1')
+        classpath 'com.google.gms:google-services:4.3.14'
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
 }
 
 allprojects {
-    repositories {
+   repositories {
+        exclusiveContent {
+            // We get React Native's Android binaries exclusively through npm,
+            // from a local Maven repo inside node_modules/react-native/.
+            // (The use of exclusiveContent prevents looking elsewhere like Maven Central
+            // and potentially getting a wrong version.)
+            filter {
+                includeGroup "com.facebook.react"
+            }
+            forRepository {
+                maven {
+                    url "$rootDir/../node_modules/react-native/android"
+                }
+            }
+        }
+
         mavenLocal()
         maven {
             // All of React Native (JS, Obj-C sources, Android binaries) is installed from npm