fix(cdk/text-field): Long multiline textfield focus issue (#30312)

When we have long multiline textfield and put cursor on almost an end (For eg. on 3rd last line) the scroll moves up to the top of textarea. This fix will cache the `scrollTop` in `resizeToFitContent` method

Fixes #20255

(cherry picked from commit dc70692)

Author: mistrykaran91

src/cdk/text-field/autosize.ts

@@ -117,6 +117,8 @@ export class CdkTextareaAutosize implements AfterViewInit, DoCheck, OnDestroy {
   private _cachedLineHeight?: number;
   /** Cached height of a textarea with only the placeholder. */
   private _cachedPlaceholderHeight?: number;
+  /** Cached scroll top of a textarea */
+  private _cachedScrollTop: number;
 
   /** Used to reference correct document/window */
   protected _document? = inject(DOCUMENT, {optional: true});
@@ -303,6 +305,7 @@ export class CdkTextareaAutosize implements AfterViewInit, DoCheck, OnDestroy {
 
     this._cacheTextareaLineHeight();
     this._cacheTextareaPlaceholderHeight();
+    this._cachedScrollTop = this._textareaElement.scrollTop;
 
     // If we haven't determined the line-height yet, we know we're still hidden and there's no point
     // in checking the height of the textarea.
@@ -367,6 +370,7 @@ export class CdkTextareaAutosize implements AfterViewInit, DoCheck, OnDestroy {
     // it to receive focus on IE and Edge.
     if (!this._destroyed.isStopped && this._hasFocus) {
       textarea.setSelectionRange(selectionStart, selectionEnd);
+      textarea.scrollTop = this._cachedScrollTop;
     }
   }
 }