Fix ActivityManagerManifestLayoutTests#testMinimalSizeDocked.

There are 2 bugs causing it to fail. The first one is we refactored the
code so that the way of getting bounds before resizing stopped to work
so we need to explicitly pass previous bounds into
adjustForMinimalTaskDimension(). The second one is getDisplayedBounds()
is not adjusted for minimal task dimension but used to calculate
containing frame.

Bug: 120794631
Test: atest ActivityManagerManifestLayoutTests#testMinimalSizeDocked &
go/wm-smoke.
Change-Id: I5fd9ea17506bbe292b7b68464894d000ddce034e