Fix "rm" command in exopackage test
Fix "rm" command in exopackage test

Summary:
The Pixel ships with (I think) busybox rm, which fails if you try to
remove a nonexistent directory.  Work around this by passing -f (force),
but only if the first command fails (because older devices don't support
-f).

Test Plan: Ran it.

fbshipit-source-id: d2e4682

daedric/buck,shybovycha/buck,robbertvanginkel/buck,dsyang/buck,romanoid/buck,zhan-xiong/buck,SeleniumHQ/buck,darkforestzero/buck,shs96c/buck,Addepar/buck,SeleniumHQ/buck,vschs007/buck,LegNeato/buck,Addepar/buck,robbertvanginkel/buck,rmaz/buck,brettwooldridge/buck,davido/buck,rmaz/buck,LegNeato/buck,grumpyjames/buck,vschs007/buck,dsyang/buck,darkforestzero/buck,Addepar/buck,daedric/buck,facebook/buck,JoelMarcey/buck,k21/buck,rmaz/buck,ilya-klyuchnikov/buck,davido/buck,vschs007/buck,rmaz/buck,vschs007/buck,JoelMarcey/buck,zpao/buck,daedric/buck,brettwooldridge/buck,shs96c/buck,k21/buck,facebook/buck,JoelMarcey/buck,JoelMarcey/buck,shs96c/buck,robbertvanginkel/buck,dsyang/buck,k21/buck,shybovycha/buck,grumpyjames/buck,darkforestzero/buck,shs96c/buck,brettwooldridge/buck,SeleniumHQ/buck,marcinkwiatkowski/buck,JoelMarcey/buck,SeleniumHQ/buck,SeleniumHQ/buck,LegNeato/buck,Addepar/buck,zpao/buck,daedric/buck,k21/buck,ilya-klyuchnikov/buck,marcinkwiatkowski/buck,romanoid/buck,rmaz/buck,LegNeato/buck,davido/buck,shybovycha/buck,LegNeato/buck,JoelMarcey/buck,darkforestzero/buck,davido/buck,Addepar/buck,robbertvanginkel/buck,facebook/buck,shybovycha/buck,k21/buck,brettwooldridge/buck,JoelMarcey/buck,grumpyjames/buck,LegNeato/buck,davido/buck,facebook/buck,SeleniumHQ/buck,ilya-klyuchnikov/buck,vschs007/buck,shs96c/buck,clonetwin26/buck,zhan-xiong/buck,robbertvanginkel/buck,daedric/buck,romanoid/buck,dsyang/buck,Addepar/buck,grumpyjames/buck,rmaz/buck,grumpyjames/buck,k21/buck,nguyentruongtho/buck,daedric/buck,marcinkwiatkowski/buck,vschs007/buck,clonetwin26/buck,marcinkwiatkowski/buck,shs96c/buck,grumpyjames/buck,kageiit/buck,facebook/buck,zhan-xiong/buck,zhan-xiong/buck,LegNeato/buck,shs96c/buck,rmaz/buck,davido/buck,davido/buck,daedric/buck,brettwooldridge/buck,marcinkwiatkowski/buck,darkforestzero/buck,grumpyjames/buck,LegNeato/buck,shybovycha/buck,shs96c/buck,grumpyjames/buck,daedric/buck,JoelMarcey/buck,shybovycha/buck,shybovycha/buck,ilya-klyuchnikov/buck,dsyang/buck,dsyang/buck,facebook/buck,brettwooldridge/buck,SeleniumHQ/buck,rmaz/buck,marcinkwiatkowski/buck,vschs007/buck,zhan-xiong/buck,JoelMarcey/buck,shybovycha/buck,zhan-xiong/buck,nguyentruongtho/buck,vschs007/buck,robbertvanginkel/buck,k21/buck,brettwooldridge/buck,SeleniumHQ/buck,daedric/buck,brettwooldridge/buck,romanoid/buck,grumpyjames/buck,k21/buck,ilya-klyuchnikov/buck,brettwooldridge/buck,nguyentruongtho/buck,kageiit/buck,JoelMarcey/buck,darkforestzero/buck,kageiit/buck,darkforestzero/buck,ilya-klyuchnikov/buck,k21/buck,clonetwin26/buck,darkforestzero/buck,clonetwin26/buck,zpao/buck,kageiit/buck,darkforestzero/buck,shs96c/buck,SeleniumHQ/buck,davido/buck,zhan-xiong/buck,LegNeato/buck,rmaz/buck,romanoid/buck,zhan-xiong/buck,ilya-klyuchnikov/buck,davido/buck,clonetwin26/buck,Addepar/buck,grumpyjames/buck,dsyang/buck,LegNeato/buck,romanoid/buck,darkforestzero/buck,zpao/buck,dsyang/buck,zpao/buck,Addepar/buck,zpao/buck,romanoid/buck,davido/buck,grumpyjames/buck,shybovycha/buck,nguyentruongtho/buck,romanoid/buck,Addepar/buck,robbertvanginkel/buck,clonetwin26/buck,marcinkwiatkowski/buck,SeleniumHQ/buck,dsyang/buck,vschs007/buck,ilya-klyuchnikov/buck,brettwooldridge/buck,dsyang/buck,clonetwin26/buck,marcinkwiatkowski/buck,robbertvanginkel/buck,clonetwin26/buck,davido/buck,daedric/buck,JoelMarcey/buck,ilya-klyuchnikov/buck,dsyang/buck,vschs007/buck,vschs007/buck,k21/buck,clonetwin26/buck,romanoid/buck,nguyentruongtho/buck,darkforestzero/buck,shybovycha/buck,LegNeato/buck,zhan-xiong/buck,darkforestzero/buck,romanoid/buck,daedric/buck,rmaz/buck,romanoid/buck,facebook/buck,shybovycha/buck,dsyang/buck,clonetwin26/buck,Addepar/buck,JoelMarcey/buck,kageiit/buck,ilya-klyuchnikov/buck,shybovycha/buck,robbertvanginkel/buck,robbertvanginkel/buck,zpao/buck,clonetwin26/buck,grumpyjames/buck,ilya-klyuchnikov/buck,romanoid/buck,marcinkwiatkowski/buck,rmaz/buck,robbertvanginkel/buck,nguyentruongtho/buck,marcinkwiatkowski/buck,daedric/buck,robbertvanginkel/buck,davido/buck,brettwooldridge/buck,darkforestzero/buck,rmaz/buck,kageiit/buck,brettwooldridge/buck,marcinkwiatkowski/buck,zhan-xiong/buck,romanoid/buck,clonetwin26/buck,Addepar/buck,SeleniumHQ/buck,shs96c/buck,vschs007/buck,clonetwin26/buck,SeleniumHQ/buck,LegNeato/buck,zhan-xiong/buck,Addepar/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,marcinkwiatkowski/buck,marcinkwiatkowski/buck,ilya-klyuchnikov/buck,vschs007/buck,zhan-xiong/buck,shs96c/buck,rmaz/buck,davido/buck,Addepar/buck,daedric/buck,zhan-xiong/buck,brettwooldridge/buck,robbertvanginkel/buck,k21/buck,k21/buck,nguyentruongtho/buck,k21/buck,dsyang/buck,shs96c/buck,shybovycha/buck,SeleniumHQ/buck,kageiit/buck,LegNeato/buck,shs96c/buck