Updates an existing policy by name

<policy>
	<general>
		<name>Firefox</name>
		<enabled>true</enabled>
		<trigger>string</trigger>
		<trigger_checkin>false</trigger_checkin>
		<trigger_enrollment_complete>false</trigger_enrollment_complete>
		<trigger_login>false</trigger_login>
		<trigger_logout>false</trigger_logout>
		<trigger_network_state_changed>false</trigger_network_state_changed>
		<trigger_startup>false</trigger_startup>
		<trigger_other>string</trigger_other>
		<frequency>Once per computer</frequency>
		<location_user_only>false</location_user_only>
		<target_drive>/</target_drive>
		<offline>false</offline>
		<category>
			<id>-1</id>
			<name>Unknown</name>
		</category>
		<network_limitations>
			<minimum_network_connection>No Minimum</minimum_network_connection>
			<any_ip_address>true</any_ip_address>
		</network_limitations>
		<network_requirements>Any</network_requirements>
		<site>
			<id>-1</id>
			<name>None</name>
		</site>
	</general>
	<scope>
		<all_computers>true</all_computers>
		<computers/>
		<computer_groups/>
		<buildings/>
		<departments/>
		<limit_to_users>
			<user_groups/>
		</limit_to_users>
		<limitations>
			<users/>
			<user_groups/>
			<network_segments/>
			<ibeacons/>
		</limitations>
		<exclusions>
			<computers/>
			<computer_groups/>
			<buildings/>
			<departments/>
			<users/>
			<user_groups/>
			<network_segments/>
			<ibeacons/>
		</exclusions>
	</scope>
	<self_service>
		<use_for_self_service>true</use_for_self_service>
		<self_service_display_name>Install Firefox</self_service_display_name>
		<install_button_text>Install</install_button_text>
		<reinstall_button_text>Reinstall</reinstall_button_text>
		<self_service_description>Install or update Firefox to version 48.0.2.</self_service_description>
		<force_users_to_view_description>false</force_users_to_view_description>
		<self_service_icon/>
		<feature_on_main_page>false</feature_on_main_page>
		<self_service_categories>
			<category>
				<id>1</id>
				<name>Applications</name>
				<display_in>true</display_in>
				<feature_in>false</feature_in>
			</category>
		</self_service_categories>
		<notification>false</notification>
		<notification>Self Service</notification>
		<notification_subject>Install Firefox</notification_subject>
		<notification_message/>
	</self_service>
</policy>