docs: fix headers in "Getting Started" code-snippets (#34321)
docs: fix headers in "Getting Started" code-snippets (#34321)

The headers of two of the code-snippets in the [Input section](https://angular.io/start#input)
of the "Getting Started" guide incorrectly referenced an non-existent
file path (`src/app/product-list/product-alerts.component.ts`).

This commit fixes the headers to show the correct file path
(`src/app/product-alerts/product-alerts.component.ts`).

Fixes #34320

PR Close #34321

Toxicable/angular,gkalpak/angular,vikerman/angular,matsko/angular,matsko/angular,brandonroberts/angular,blesh/angular,snaptech/angular,StephenFluin/angular,JiaLiPassion/angular,alxhub/angular,vikerman/angular,IdeaBlade/angular,vikerman/angular,manekinekko/angular,ocombe/angular,wKoza/angular,alxhub/angular,shairez/angular,JiaLiPassion/angular,brandonroberts/angular,angular/angular,shairez/angular,wKoza/angular,filipesilva/angular,manekinekko/angular,angular/angular,snaptech/angular,mgechev/angular,ocombe/angular,mgechev/angular,filipesilva/angular,angular-indonesia/angular,gnomeontherun/angular,filipesilva/angular,snaptech/angular,gkalpak/angular,Toxicable/angular,angular/angular,mgechev/angular,mgechev/angular,vikerman/angular,shairez/angular,blesh/angular,gdi2290/angular,manekinekko/angular,angular-indonesia/angular,StephenFluin/angular,IdeaBlade/angular,filipesilva/angular,gdi2290/angular,Toxicable/angular,snaptech/angular,gkalpak/angular,gdi2290/angular,gnomeontherun/angular,Toxicable/angular,gnomeontherun/angular,Toxicable/angular,snaptech/angular,ocombe/angular,gdi2290/angular,StephenFluin/angular,snaptech/angular,wKoza/angular,IdeaBlade/angular,ocombe/angular,IdeaBlade/angular,ocombe/angular,matsko/angular,alxhub/angular,StephenFluin/angular,mgechev/angular,matsko/angular,angular-indonesia/angular,IdeaBlade/angular,alxhub/angular,brandonroberts/angular,JiaLiPassion/angular,blesh/angular,alxhub/angular,shairez/angular,StephenFluin/angular,angular/angular,matsko/angular,wKoza/angular,gdi2290/angular,manekinekko/angular,manekinekko/angular,shairez/angular,brandonroberts/angular,Toxicable/angular,manekinekko/angular,angular-indonesia/angular,gnomeontherun/angular,wKoza/angular,filipesilva/angular,gdi2290/angular,vikerman/angular,ocombe/angular,gkalpak/angular,blesh/angular,brandonroberts/angular,blesh/angular,vikerman/angular,JiaLiPassion/angular,brandonroberts/angular,wKoza/angular