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/process-services-cloud/src/lib/process/start-process/components/start-process-cloud.component.html

@@ -150,8 +150,7 @@
         }
         @if (showStartProcessButton$ | async) {
             <button
-                color="primary"
-                mat-raised-button
+                mat-flat-button
                 [disabled]="disableStartButton || !isProcessFormValid"
                 (click)="startProcess()"
                 data-automation-id="btn-start"

lib/process-services-cloud/src/lib/task/task-form/components/user-task-cloud/user-task-cloud.component.html

@@ -77,7 +77,7 @@
                         <ng-template [ngTemplateOutlet]="taskFormCloudButtons" />
                         <button
                             *ngIf="canCompleteTask()"
-                            mat-button
+                            mat-flat-button
                             adf-cloud-complete-task
                             [appName]="appName"
                             [taskId]="taskId"