title: Error 'mat-dialog-content' is not a known element
body: <p>I am trying to create a login form using angular-material. I am using <code>@angular/material": "^7.3.0</code>. </p>
  
  <p>In <code>app.module.ts</code> i have imported the following and placed them in the imports array as well, </p>
  
  <pre><code>import {
    MatToolbarModule, MatFormFieldModule, MatInputModule,
    MatOptionModule, MatSelectModule, MatIconModule, 
    MatButtonModule, MatCardModule, MatTableModule,
    MatDividerModule, MatSnackBarModule
  } from '@angular/material';
  </code></pre>
  
  <p>In <code>message.components.ts</code> i have the following</p>
  
  <pre><code>import { MatDialogRef, MAT_DIALOG_DATA, MatDialog } from '@angular/material';
  import { Component, OnInit, Inject, Injectable } from '@angular/core';
  
  @Component({
    selector: 'app-message',
    templateUrl: './message.component.html',
    styleUrls: ['./message.component.css']
  })
  
  export class MessageComponent implements OnInit {
    constructor(private dialogRef: MatDialogRef&lt;MessageComponent&gt;, 
                 @Inject(MAT_DIALOG_DATA) public data: any) {
            }
            public closeMe() {
              this.dialogRef.close();
            }
            ngOnInit() {
            }
          }
  </code></pre>
  
  <p>In my template message.component.html i have,</p>
  
  <pre><code>&lt;h1 mat-dialog-title&gt;Message&lt;/h1&gt;
  &lt;mat-dialog-content&gt; &lt;/mat-dialog-content&gt;
  &lt;mat-dialog-actions&gt;
    &lt;button mat-raised-button (click)="closeMe()"&gt;Close&lt;/button&gt;
  &lt;/mat-dialog-actions&gt;
  </code></pre>
  
  <p>I am getting the errors for mat-dialog-actions &amp; mat-dialog-content,</p>
  
  <pre><code>'mat-dialog-content' is not a known element:
  'mat-dialog-actions' is not a known element:
  </code></pre>
  
  <p>As per the documentation <a href="https://material.angular.io/components/dialog/overview" rel="noreferrer">angular-material</a> both directives are available. What could be wrong in the code ? Thank you in advance.</p>