fix(bazel): ng_package not generating UMD bundles on windows (#27200)
fix(bazel): ng_package not generating UMD bundles on windows (#27200)

* Fixes that `ng_package` does not work generate UMD bundles on Windows because the `esm5/` files are not written to the output directory. This is because `rootDirs` and `rootDir` are posix paths and cause invalid relative paths when mixed with Windows backslash paths.

PR Close #27200

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