DON-877: Save my details dialog screen reader adjustments:

- Stop auto-focusing on the 'cancel' button so it doesn't have to be
  read first
- Set entire dialog content as 'aria-live' so it is automatically read
  out when the dialog is opened
- Change link copy from "Learn more" to "Learn more about stripe"

src/app/donation-complete/donation-complete-set-password-dialog.html

@@ -1,11 +1,11 @@
-<app-popup-standalone>
+<app-popup-standalone aria-live="polite">
   <h2 mat-dialog-title>Set a password</h2>
 
   <mat-dialog-content class="mat-typography">
     <form [formGroup]="form">
       <p>Email address: <strong>{{ data.person.email_address }}</strong></p>
 
-      <p><strong>Your last payment card</strong> will be saved for reuse. It is held securely only with Stripe. <a href="https://stripe.com/docs/security/stripe" target="_blank"><mat-icon class="b-va-bottom" aria-hidden="false" aria-label="Open in new tab">open_in_new</mat-icon> Learn more</a>.</p>
+      <p><strong>Your last payment card</strong> will be saved for reuse. It is held securely only with Stripe. <a href="https://stripe.com/docs/security/stripe" target="_blank"><mat-icon class="b-va-bottom" aria-hidden="false" aria-label="Open in new tab">open_in_new</mat-icon> Learn more about Stripe</a>.</p>
 
       <mat-form-field class="b-w-100" color="primary">
         <mat-label for="password">Password (at least {{ minPasswordLength }} characters)</mat-label>
@@ -21,6 +21,6 @@ <h2 mat-dialog-title>Set a password</h2>
 
   <mat-dialog-actions align="end">
     <button mat-raised-button id="createAccountButton" [disabled]="!form.valid" (click)="set()" color="primary">Create Account</button>
-    <button mat-raised-button [mat-dialog-close]="false" cdkFocusInitial color="accent">Cancel</button>
+    <button mat-raised-button [mat-dialog-close]="false" color="accent">Cancel</button>
   </mat-dialog-actions>
 </app-popup-standalone>