Check List for Generate Signed APK Android

Manifest file

• Provide the Package name
• Provide the app version name (should be higher value if the app already submitted in playstore). For updated apps, version name depends on the features. If the updated version is major release, increase the digit value. If the updated version is minor release, just increase the decimal value. 
  • Ex: 1.0,1.1 etc,
• Provide the app version code (should be higher value if the app already submitted in playstore)
  • Ex: 1,2,3… (Integer values)
• If your app wants run on future sdk versions don’t mention max-sdk.
• Minimum SDk version (which is, app will support the from this lower sdk version)
• If App working with network call, give the Internet permission.
• <uses-feature />, if the app required the hardware components mandatory, you should mention that in <user-feature/> tag with attribute  required=true
• Add require permissions in side <uses-permission> tag.
• App should be in release mode,(android:debuggable="false")
• Declare all your activities,services and receivers with required attributes.

1. Remove logs or comment all(not mandatory,but it is good to remove)

2. Pointing all service calls to production server.

3. Generate signed apk.
   a) For generating signed apk we need keystore file, create a keystore file.
   b) Generate Signed apk with keystore file (should be same keystore file for future
   releases)

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="package name"

android:versionCode="1"

android:versionName="1.0">

    <uses-permission android:name="android.permission.INTERNET" />

    <uses-sdk   android:minSdkVersion="minimum version "/>

<uses-feature android:glEsVersion="0x00010001"

         android:required="true" />

   <application android:name="App name"

    android:debuggable="false"

    android:icon="app_icon"  android:label="app_name" 

    android:theme="@style/AppTheme">

    <activity android:name="Packagename.Activity Name"

     >

        <intent-filter>

            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />

        </intent-filter>

    </activity>

     <activity android:name="Packagename.Next Activity" />

If we use the Gradle Build Tool 

All we need to maintain the version details, dependencies in the App Level gradle file

build.gradle