docs(aio): update HTTP error test example (#22844)
docs(aio): update HTTP error test example (#22844)

Update the example to match the description preceding it, which refers to the
use of the error method and ErrorEvent rather than the flush method with a
non-2xx status as shown previously.

PR Close #22844

alexeagle/angular,vikerman/angular,angular/angular,gkalpak/angular,sarunint/angular,filipesilva/angular,snaptech/angular,hansl/angular,mhevery/angular,StephenFluin/angular,snaptech/angular,manekinekko/angular,IdeaBlade/angular,kegluneq/angular,vikerman/angular,mhevery/angular,wKoza/angular,mgiambalvo/angular,Brocco/angular,filipesilva/angular,mzgol/angular,ocombe/angular,heathkit/angular,vicb/angular,Toxicable/angular,mlaval/angular,mlaval/angular,mzgol/angular,IdeaBlade/angular,snaptech/angular,alxhub/angular,IgorMinar/angular,angular-indonesia/angular,juristr/angular,sarunint/angular,ValtoFrameworks/Angular-2,sarunint/angular,gnomeontherun/angular,angular-indonesia/angular,vicb/angular,kegluneq/angular,IgorMinar/angular,hansl/angular,trshafer/angular,alxhub/angular,mlaval/angular,mzgol/angular,manekinekko/angular,matsko/angular,manekinekko/angular,NathanWalker/angular,matsko/angular,gdi2290/angular,shairez/angular,JiaLiPassion/angular,jasonaden/angular,petebacondarwin/angular,JiaLiPassion/angular,jonrimmer/angular,Brocco/angular,ultrasonicsoft/angular,vikerman/angular,kara/angular,trshafer/angular,vikerman/angular,gdi2290/angular,mgiambalvo/angular,snaptech/angular,StephenFluin/angular,StephenFluin/angular,mgiambalvo/angular,kegluneq/angular,mgol/angular,ValtoFrameworks/Angular-2,mlaval/angular,gdi2290/angular,hansl/angular,Brocco/angular,wKoza/angular,Brocco/angular,mprobst/angular,wKoza/angular,jasonaden/angular,matsko/angular,manekinekko/angular,ocombe/angular,angular-indonesia/angular,alexeagle/angular,alexeagle/angular,jonrimmer/angular,ValtoFrameworks/Angular-2,StephenFluin/angular,vicb/angular,trshafer/angular,alxhub/angular,sarunint/angular,juristr/angular,petebacondarwin/angular,trshafer/angular,alexeagle/angular,ValtoFrameworks/Angular-2,ultrasonicsoft/angular,mgol/angular,vicb/angular,gnomeontherun/angular,heathkit/angular,kara/angular,blesh/angular,sarunint/angular,jasonaden/angular,petebacondarwin/angular,mgechev/angular,jasonaden/angular,filipesilva/angular,mgechev/angular,gnomeontherun/angular,alxhub/angular,shairez/angular,alexeagle/angular,ultrasonicsoft/angular,brandonroberts/angular,mzgol/angular,jonrimmer/angular,brandonroberts/angular,ultrasonicsoft/angular,angular/angular,mhevery/angular,mhevery/angular,jonrimmer/angular,blesh/angular,IgorMinar/angular,kara/angular,hansl/angular,ocombe/angular,NathanWalker/angular,Toxicable/angular,Toxicable/angular,snaptech/angular,IdeaBlade/angular,NathanWalker/angular,mgol/angular,jonrimmer/angular,mgiambalvo/angular,brandonroberts/angular,mgechev/angular,petebacondarwin/angular,brandonroberts/angular,NathanWalker/angular,heathkit/angular,IgorMinar/angular,mprobst/angular,alexeagle/angular,juristr/angular,Toxicable/angular,kegluneq/angular,petebacondarwin/angular,gkalpak/angular,jonrimmer/angular,mprobst/angular,IgorMinar/angular,JiaLiPassion/angular,angular/angular,shairez/angular,filipesilva/angular,manekinekko/angular,mzgol/angular,ValtoFrameworks/Angular-2,sarunint/angular,Brocco/angular,mgol/angular,mgechev/angular,IdeaBlade/angular,gdi2290/angular,ultrasonicsoft/angular,wKoza/angular,manekinekko/angular,matsko/angular,ocombe/angular,alxhub/angular,gnomeontherun/angular,kegluneq/angular,shairez/angular,hansl/angular,kara/angular,blesh/angular,jasonaden/angular,mhevery/angular,mprobst/angular,mhevery/angular,matsko/angular,vicb/angular,ocombe/angular,wKoza/angular,kegluneq/angular,Toxicable/angular,NathanWalker/angular,shairez/angular,trshafer/angular,mlaval/angular,gkalpak/angular,blesh/angular,mgol/angular,vicb/angular,JiaLiPassion/angular,mprobst/angular,StephenFluin/angular,wKoza/angular,kara/angular,heathkit/angular,petebacondarwin/angular,mgiambalvo/angular,vikerman/angular,ocombe/angular,vikerman/angular,filipesilva/angular,mzgol/angular,juristr/angular,brandonroberts/angular,snaptech/angular,angular/angular,mgechev/angular,jasonaden/angular,NathanWalker/angular,heathkit/angular,angular-indonesia/angular,heathkit/angular,hansl/angular,ultrasonicsoft/angular,trshafer/angular,Toxicable/angular,IgorMinar/angular,blesh/angular,gkalpak/angular,brandonroberts/angular,mgol/angular,gdi2290/angular,IdeaBlade/angular,gdi2290/angular,mprobst/angular,Brocco/angular,juristr/angular,juristr/angular,kara/angular