Better building of settings output, also giving others all the freedom they...

Better building of settings output, also giving others all the freedom they need to add per the spec

eth-amp-analytics-wp.php

@@ -108,25 +108,23 @@ class ETH_AMP_Analytics_WP {
 	 *
 	 */
 	public function action_amp_post_template_footer( $amp_template ) {
-		$triggers = array(
-			'trackPageview' => array(
-				'on'      => 'visible',
-				'request' => 'pageview',
+		$output = array(
+			'vars'     => array(
+				'account' => $this->get_option( 'property_id' ),
+			),
+			'triggers' => array(
+				'trackPageview' => array(
+					'on'      => 'visible',
+					'request' => 'pageview',
+				),
 			),
 		);
 
-		$triggers = apply_filters( 'eth_amp_analytics_wp_ga_triggers', $triggers, $amp_template );
+		$output = apply_filters( 'eth_amp_analytics_wp_ga_settings_js', $output );
 
 		?>
 		<amp-analytics type="googleanalytics" id="analytics1">
-			<script type="application/json">
-				{
-					"vars": {
-						"account": "<?php echo esc_js( $this->options['property_id'] ); ?>"
-					},
-					"triggers": <?php wp_json_encode( $triggers ); ?>
-				}
-			</script>
+			<script type="application/json"><?php echo wp_json_encode( $output ); ?></script>
 		</amp-analytics>
 		<?php
 	}