DO NOT MERGE: Add DENSITY_450

Add 450dpi as a supported screen density.
This change follows up below change Id : Iac673eae2d82c27d96e279c076454af2f5933208

Originally 600dpi was added to support sw384 with WQHD resolution,
though it was lack of for the cases when resolution is FHD resolution. (In case of other resolutions, there already exist 300 and 200 for HD and WVGA resolutions).

Bug: 78283907
Test: run android.dpi.cts.ConfigurationTest#testScreenConfiguration and android.app.cts.ActivityManagerMemoryClassTest#testGetMemoryClass
(cherry picked from commit 13ca0450ede3eedf7d34bbd0b69525cb6ebc63f1)

Change-Id: Ide0baba183c7dea962610d16f18fecbd0dc62567