private boolean declaresRequestInstallPermission(final String pkg) {
		final PackageInfo pkg_info = Apps.of(this).getPackageInfo(pkg, GET_PERMISSIONS);
		if (pkg_info == null) return true;		// Unable to detect its declared permissions, just let it pass.
		if (pkg_info.requestedPermissions == null) return false;
		for (final String requested_permission : pkg_info.requestedPermissions)
			if (REQUEST_INSTALL_PACKAGES.equals(requested_permission)) return true;
		return false;
	}
@param base_pkg the base package name for split APK installation, or null for full installation.
installer/src/main/java/com/oasisfeng/island/installer/AppInstallerActivity.java