changed erroneous `flex="22"` to `flex="20"`
changed erroneous `flex="22"` to `flex="20"`

Example code had `flex="22"` while MD spec and angular material docs say multiples of 5. Changed to `flex="20"`

Closes #8637

marekmicek/material,vertazzar/material,SamDLT/material,SamDLT/material,Frank3K/material,miguelcobain/material,miguelcobain/material,clshortfuse/material,angular/material,hayloft/material,graingert/material,david-gang/material,DevVersion/material,profoundry-us/material,oostmeijer/material,pwistbac/material,oostmeijer/material,pwistbac/material,HipsterZipster/material,hayloft/material,profoundry-us/material,SamDLT/material,david-gang/material,SamDLT/material,imjoeco/material,miguelcobain/material,angular/material,imjoeco/material,david-gang/material,Splaktar/material,Frank3K/material,angular/material,bluebirdtech/material,epelc/material,miguelcobain/material,graingert/material,imjoeco/material,Splaktar/material,j3ski/material,oostmeijer/material,j3ski/material,marekmicek/material,clshortfuse/material,angular/material,HipsterZipster/material,Splaktar/material,ServiceManagementGroup/material,gkalpak/material,marekmicek/material,clshortfuse/material,clshortfuse/material,pwistbac/material,gkalpak/material,welkinhealth/material,epelc/material,vertazzar/material,DevVersion/material,david-gang/material,hayloft/material,daniel-nagy/material,welkinhealth/material,ilovett/material,gkalpak/material,pwistbac/material,epelc/material,imjoeco/material,ServiceManagementGroup/material,j3ski/material,crisbeto/material,vertazzar/material,daniel-nagy/material,ilovett/material,bluebirdtech/material,DevVersion/material,marekmicek/material,bluebirdtech/material,daniel-nagy/material,crisbeto/material,graingert/material,ilovett/material,ilovett/material,Frank3K/material,ServiceManagementGroup/material,gkalpak/material,bluebirdtech/material,ServiceManagementGroup/material,HipsterZipster/material,vertazzar/material,crisbeto/material,welkinhealth/material,welkinhealth/material,crisbeto/material,Splaktar/material,j3ski/material,hayloft/material,Frank3K/material,DevVersion/material,epelc/material,HipsterZipster/material,daniel-nagy/material,graingert/material,oostmeijer/material,profoundry-us/material,profoundry-us/material