test(ivy): mock the filesystem in ngcc main() integration tests (#25557)
test(ivy): mock the filesystem in ngcc main() integration tests (#25557)

Bazel does not like the filesystem being modified.
This commit a temporary mock filesystem that can be modified as needed.

PR Close #25557

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