fix(input): increase placeholder contrast on focus (#9804)
fix(input): increase placeholder contrast on focus (#9804)

According to Material Design spec and a11y accessibility, a focused
text field should have a secondary text opacity

* Change input placeholder color from foreground-3 to foreground-2 on focus

Fixes #8903
pwistbac/material,bluebirdtech/material,pwistbac/material,marekmicek/material,profoundry-us/material,marekmicek/material,Splaktar/material,angular/material,oostmeijer/material,david-gang/material,ilovett/material,graingert/material,bluebirdtech/material,graingert/material,profoundry-us/material,david-gang/material,crisbeto/material,DevVersion/material,clshortfuse/material,angular/material,SamDLT/material,Frank3K/material,crisbeto/material,clshortfuse/material,Splaktar/material,marekmicek/material,imjoeco/material,DevVersion/material,hayloft/material,angular/material,crisbeto/material,SamDLT/material,marekmicek/material,daniel-nagy/material,david-gang/material,hayloft/material,ServiceManagementGroup/material,Frank3K/material,hayloft/material,Frank3K/material,imjoeco/material,miguelcobain/material,bluebirdtech/material,miguelcobain/material,imjoeco/material,miguelcobain/material,profoundry-us/material,daniel-nagy/material,ServiceManagementGroup/material,imjoeco/material,clshortfuse/material,ilovett/material,Splaktar/material,clshortfuse/material,SamDLT/material,DevVersion/material,ilovett/material,daniel-nagy/material,oostmeijer/material,bluebirdtech/material,graingert/material,pwistbac/material,Splaktar/material,ServiceManagementGroup/material,miguelcobain/material,vertazzar/material,david-gang/material,oostmeijer/material,crisbeto/material,hayloft/material,profoundry-us/material,vertazzar/material,oostmeijer/material,DevVersion/material,ServiceManagementGroup/material,vertazzar/material,graingert/material,ilovett/material,pwistbac/material,daniel-nagy/material,Frank3K/material,SamDLT/material,vertazzar/material,angular/material