Add flicker test for minimum window size constraints.

Video: https://drive.google.com/file/d/1Rov6-lMMErXgKZm0H-rKbXqaRz2ZmzzV/view?usp=drive_link
Test: atest
com.android.wm.shell.flicker.service.desktopmode.flicker.ResizeAppToMinimumWindowSizePortrait
Flag: EXEMPT adding test
Fixes: 350698619
Fixes: 351141253

Change-Id: I021275d5b028aa1698824f70aa37a06241e562ac