fix: textarea height with multiline placeholder

Author: szuperaz

projects/stream-chat-angular/src/lib/message-input/autocomplete-textarea/autocomplete-textarea.component.spec.ts

@@ -473,7 +473,7 @@ describe('AutocompleteTextareaComponent', () => {
 
   it('should set initial height of the textarea based on value received', () => {
     const textarea = queryTextarea();
-    textarea!.value = 'This is my \n multiline message';
+    component.value = 'This is my \n multiline message';
     component.ngAfterViewInit();
     fixture.detectChanges();
 

projects/stream-chat-angular/src/lib/message-input/autocomplete-textarea/autocomplete-textarea.component.ts

@@ -208,7 +208,7 @@ export class AutocompleteTextareaComponent
       'info',
       '[Autocomplete textarea] View inited'
     );
-    if (this.messageInput.nativeElement.scrollHeight > 0) {
+    if (this.messageInput.nativeElement.scrollHeight > 0 && this.value) {
       this.adjustTextareaHeight();
     }
   }

projects/stream-chat-angular/src/lib/message-input/textarea/textarea.component.spec.ts

@@ -163,7 +163,7 @@ describe('TextareaComponent', () => {
 
   it('should set initial height of the textarea based on value received', () => {
     const textarea = queryTextarea();
-    textarea!.value = 'This is my \n multiline message';
+    component.value = 'This is my \n multiline message';
     component.ngAfterViewInit();
     fixture.detectChanges();
 

projects/stream-chat-angular/src/lib/message-input/textarea/textarea.component.ts

@@ -81,7 +81,7 @@ export class TextareaComponent
   }
 
   ngAfterViewInit(): void {
-    if (this.messageInput.nativeElement.scrollHeight > 0) {
+    if (this.messageInput.nativeElement.scrollHeight > 0 && this.value) {
       this.adjustTextareaHeight();
     }
   }