fix(progressbar): use PercentPipe by default (#3777)
fix(progressbar): use PercentPipe by default (#3777)

Closes #3700 
benouat/ng-bootstrap,fbasso/ng-bootstrap,jnizet/ng-bootstrap,fbasso/ng-bootstrap,ng-bootstrap/ng-bootstrap,maxokorokov/core,benouat/ng-bootstrap,jnizet/ng-bootstrap,maxokorokov/core,ng-bootstrap/ng-bootstrap,ng-bootstrap/ng-bootstrap,fbasso/ng-bootstrap,benouat/ng-bootstrap,maxokorokov/core,jnizet/ng-bootstrap,maxokorokov/core,ng-bootstrap/ng-bootstrap,benouat/ng-bootstrap,fbasso/ng-bootstrap,jnizet/ng-bootstrap