Added min width and height as 48dp for RationaleContent

Bug: 317742981
Test: Manual verification, before and after screenshot attached in the bug
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a369b6a38e8556acc4eb0f3011159f341e1cd544)
Merged-In: Ib7b08f0d0fdf707d4161199d746edd6b69ee61ce
Change-Id: Ib7b08f0d0fdf707d4161199d746edd6b69ee61ce
Submitting changes based on b/317742981#comment8