♻️ Apply latest JS structure from ApplePay Gateway

- Partially addresses the known display bug
- Simplifies maintainance between both gateways
- Reduces component-internal redundancies

modules/ppcp-googlepay/src/Assets/Button.php

@@ -290,6 +290,7 @@ class Button implements ButtonInterface {
 				$render_placeholder,
 				function () {
 					$this->googlepay_button();
+					$this->hide_gateway_until_eligible();
 				},
 				21
 			);
@@ -303,6 +304,7 @@ class Button implements ButtonInterface {
 				$render_placeholder,
 				function () {
 					$this->googlepay_button();
+					$this->hide_gateway_until_eligible();
 				},
 				21
 			);
@@ -335,6 +337,21 @@ class Button implements ButtonInterface {
 		<?php
 	}
 
+	/**
+	 * Outputs an inline CSS style that hides the Google Pay gateway (on Classic Checkout).
+	 * The style is removed by `GooglepayButton.js` once the eligibility of the payment method
+	 * is confirmed.
+	 *
+	 * @return void
+	 */
+	protected function hide_gateway_until_eligible() : void {
+		?>
+		<style id="ppcp-hide-google-pay">
+			.wc_payment_method.payment_method_ppcp-googlepay { : none}
+		</style>
+		<?php
+	}
+
 	/**
 	 * Enqueues scripts/styles.
 	 */