@Override protected void onCreate(@Nullable final Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		if (! prepare()) finish();
	}
App installer with following capabilities:
<ul>
<li> Install APK from Mainland into Island, and vice versa.
<li> Install app without user consent
</ul>
Created by Oasis on 2018-11-12.
installer/src/main/java/com/oasisfeng/island/installer/AppInstallerActivity.java