Untiy android plugin class not found exception

I'm writing an android plugin for unity to be able to check if notifications are enabled for the game. I have one java class with a method for checking if notifications are enabled. When i build the plugin and then the .apk with unity everything works fine. But after installation, when calling the mehthod i get the following exception:

java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/core/app/NotificationManagerCompat;

The Java class

package com.example.plugin;

import android.app.Activity;
import androidx.core.app.NotificationManagerCompat;

public class NotificationPlugin {

    public static boolean areNotificationEnabled(Activity unityActivity) {
        return NotificationManagerCompat.from(unityActivity).areNotificationsEnabled();
    }
}

buld.gradle

apply plugin: 'com.android.library'

android {
    compileSdkVersion 29
    buildToolsVersion "29.0.2"


    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
        consumerProguardFiles 'consumer-rules.pro'
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    implementation 'androidx.appcompat:appcompat:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.0'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
}

gradle.properties

org.gradle.jvmargs=-Xmx1536m
android.useAndroidX=true
android.enableJetifier=true

Haven't found a solution anywhere else yet. Thank in advance. It's probably a super simple fix that i miss.

Update

• Custom gradle.properties in unity set with android.enableJetifier and android.useAndroidX set to true
• Jetifier was enabled in unity
• Androidx.Core libary was added to the dependencies of the gradle.build file of the plugin

None of the above solved the issue

Solution

As Hamid Yusifli suggested in his answer a custom gradle build template needs to be enabled (Project Settings>Player>Publishing Settings>Custom Main Gralde Template) and the dependencies for the libary need to be added (implementation 'androidx.core:core:1.5.0' in my case). This solved the issue.