add support for parsing buckets from variables of prom.Linear and prom.Expo helpers
add support for parsing buckets from variables of prom.Linear and prom.Expo helpers

Change-Id: I61bb46dcbdc02d506da563bc7973430ecef8c364

kevin-wangzefeng/kubernetes,mkumatag/kubernetes,lojies/kubernetes,soltysh/kubernetes,k82cn/kubernetes,liggitt/kubernetes,GulajavaMinistudio/kubernetes,matthyx/kubernetes,mahak/kubernetes,MikeSpreitzer/kubernetes,thockin/kubernetes,jackfrancis/kubernetes,deads2k/kubernetes,gnufied/kubernetes,enj/kubernetes,dims/kubernetes,carlory/kubernetes,enj/kubernetes,olivierlemasle/kubernetes,dims/kubernetes,mkumatag/kubernetes,jessfraz/kubernetes,liggitt/kubernetes,jackfrancis/kubernetes,carlory/kubernetes,mahak/kubernetes,lojies/kubernetes,liggitt/kubernetes,BenTheElder/kubernetes,jessfraz/kubernetes,liggitt/kubernetes,dims/kubernetes,carlory/kubernetes,mahak/kubernetes,deads2k/kubernetes,jessfraz/kubernetes,ping035627/kubernetes,carlory/kubernetes,mkumatag/kubernetes,warmchang/kubernetes,jackfrancis/kubernetes,kubernetes/kubernetes,olivierlemasle/kubernetes,mahak/kubernetes,matthyx/kubernetes,mahak/kubernetes,PiotrProkop/kubernetes,warmchang/kubernetes,PiotrProkop/kubernetes,soltysh/kubernetes,matthyx/kubernetes,jsafrane/kubernetes,jsafrane/kubernetes,dims/kubernetes,jsafrane/kubernetes,kevin-wangzefeng/kubernetes,BenTheElder/kubernetes,mkumatag/kubernetes,k82cn/kubernetes,gnufied/kubernetes,k82cn/kubernetes,GulajavaMinistudio/kubernetes,thockin/kubernetes,soltysh/kubernetes,kevin-wangzefeng/kubernetes,jsafrane/kubernetes,MikeSpreitzer/kubernetes,mkumatag/kubernetes,gnufied/kubernetes,PiotrProkop/kubernetes,kubernetes/kubernetes,ping035627/kubernetes,dims/kubernetes,jessfraz/kubernetes,kubernetes/kubernetes,mosoft521/kubernetes,kevin-wangzefeng/kubernetes,ping035627/kubernetes,MikeSpreitzer/kubernetes,PiotrProkop/kubernetes,matthyx/kubernetes,thockin/kubernetes,kubernetes/kubernetes,olivierlemasle/kubernetes,ping035627/kubernetes,lojies/kubernetes,kevin-wangzefeng/kubernetes,mosoft521/kubernetes,gnufied/kubernetes,soltysh/kubernetes,gnufied/kubernetes,matthyx/kubernetes,GulajavaMinistudio/kubernetes,carlory/kubernetes,thockin/kubernetes,GulajavaMinistudio/kubernetes,jackfrancis/kubernetes,soltysh/kubernetes,warmchang/kubernetes,jackfrancis/kubernetes,BenTheElder/kubernetes,deads2k/kubernetes,warmchang/kubernetes,olivierlemasle/kubernetes,jsafrane/kubernetes,warmchang/kubernetes,MikeSpreitzer/kubernetes,MikeSpreitzer/kubernetes,olivierlemasle/kubernetes,lojies/kubernetes,mosoft521/kubernetes,enj/kubernetes,GulajavaMinistudio/kubernetes,enj/kubernetes,jessfraz/kubernetes,kubernetes/kubernetes,BenTheElder/kubernetes,PiotrProkop/kubernetes,lojies/kubernetes,liggitt/kubernetes,thockin/kubernetes,deads2k/kubernetes,mosoft521/kubernetes,deads2k/kubernetes,enj/kubernetes,ping035627/kubernetes,k82cn/kubernetes,BenTheElder/kubernetes,mosoft521/kubernetes,k82cn/kubernetes