1.The android:versionCode attribute in the manifest file must be incremented and the APK file must be signed with the same private key.
2.The android:versionCode attribute in the manifest file must be same and the APK file must be signed with the same private key.
3.The android:versionCode attribute in the manifest file must be incremented and the APK file must be signed with the new private key.
4.The android:versionCode attribute in the manifest file must be same and the APK file must be signed with the new private key.