AAE-40934 style: replace mat-raise-button with mat-flat-button (#11502)

* AAE-40934 style: replace mat-raise-button with mat-flat-button

* AAE-40934 style: remove unnecessary color declarations from material buttons, rely on MD3 default primary button color

lib/core/src/lib/form/components/widgets/json/json.widget.html

@@ -4,5 +4,5 @@
             {{ field.name | translate }}
         </label>
     </div>
-    <button mat-raised-button color="primary" (click)="view()">json</button>
+    <button mat-flat-button (click)="view()">json</button>
 </div>

lib/core/src/lib/form/components/widgets/repeat/repeat.widget.html

@@ -14,8 +14,7 @@
         @let shouldDisplayAddRowButton = !element.field.params.maxNumberOfRows || (element.field.params.maxNumberOfRows > element.field.rows.length);
         @if (shouldDisplayAddRowButton) {
             <button 
-                mat-button
-                color="primary"
+                mat-flat-button
                 class="adf-container-widget-row-action"
                 [disabled]="element.field.readOnly"
                 (click)="addRow()"